(improvement)(chat|common|headless|webapp) 结果分析，改写伪流式输出，加快响应速度 (#2395)

guilinlewis · web-flow · commit 04b1edb2e2ac · 2025-10-22T15:37:50.000+08:00
diff --git a/chat/api/src/main/java/com/tencent/supersonic/chat/api/pojo/request/ChatExecuteReq.java b/chat/api/src/main/java/com/tencent/supersonic/chat/api/pojo/request/ChatExecuteReq.java
@@ -18,4 +18,5 @@ public class ChatExecuteReq {
     private int parseId;
     private String queryText;
     private boolean saveAnswer;
+    private boolean streamingResult;
 }
diff --git a/chat/server/src/main/java/com/tencent/supersonic/chat/server/parser/NL2SQLParser.java b/chat/server/src/main/java/com/tencent/supersonic/chat/server/parser/NL2SQLParser.java
@@ -32,6 +32,7 @@
 import dev.langchain4j.model.output.Response;
 import dev.langchain4j.provider.ModelProvider;
 import lombok.extern.slf4j.Slf4j;
+import org.apache.commons.lang3.StringUtils;
 import org.slf4j.Logger;
 import org.slf4j.LoggerFactory;
 
@@ -171,23 +172,25 @@ private void rewriteMultiTurn(ParseContext parseContext, QueryNLReq queryNLReq)
             return;
         }
 
-        // derive mapping result of current question and parsing result of last question.
-        ChatLayerService chatLayerService = ContextUtils.getBean(ChatLayerService.class);
-        MapResp currentMapResult = chatLayerService.map(queryNLReq);
-
         List<QueryResp> historyQueries =
                 getHistoryQueries(parseContext.getRequest().getChatId(), 1);
         if (historyQueries.isEmpty()) {
             return;
         }
         QueryResp lastQuery = historyQueries.get(0);
         SemanticParseInfo lastParseInfo = lastQuery.getParseInfos().get(0);
-        Long dataId = lastParseInfo.getDataSetId();
+        String histSQL = lastParseInfo.getSqlInfo().getCorrectedS2SQL();
+        if (StringUtils.isBlank(histSQL)) // 优化性能,如果问答不是chat bi 则无需重写，因为数据都不全
+            return;
 
+        // derive mapping result of current question and parsing result of last question.
+        ChatLayerService chatLayerService = ContextUtils.getBean(ChatLayerService.class);
+        MapResp currentMapResult = chatLayerService.map(queryNLReq); // 优化性能 ,只有满足条件才mapping
+
+        Long dataId = lastParseInfo.getDataSetId();
         String curtMapStr =
                 generateSchemaPrompt(currentMapResult.getMapInfo().getMatchedElements(dataId));
         String histMapStr = generateSchemaPrompt(lastParseInfo.getElementMatches());
-        String histSQL = lastParseInfo.getSqlInfo().getCorrectedS2SQL();
 
         Map<String, Object> variables = new HashMap<>();
         variables.put("current_question", currentMapResult.getQueryText());
diff --git a/chat/server/src/main/java/com/tencent/supersonic/chat/server/processor/execute/DataInterpretProcessor.java b/chat/server/src/main/java/com/tencent/supersonic/chat/server/processor/execute/DataInterpretProcessor.java
@@ -1,13 +1,20 @@
 package com.tencent.supersonic.chat.server.processor.execute;
 
+import com.alibaba.fastjson.JSON;
+import com.alibaba.fastjson.JSONObject;
 import com.tencent.supersonic.chat.api.pojo.response.QueryResult;
 import com.tencent.supersonic.chat.server.agent.Agent;
+import com.tencent.supersonic.chat.server.persistence.dataobject.ChatQueryDO;
+import com.tencent.supersonic.chat.server.persistence.repository.ChatQueryRepository;
 import com.tencent.supersonic.chat.server.pojo.ExecuteContext;
 import com.tencent.supersonic.common.pojo.ChatApp;
 import com.tencent.supersonic.common.pojo.enums.AppModule;
 import com.tencent.supersonic.common.util.ChatAppManager;
+import com.tencent.supersonic.common.util.ContextUtils;
 import dev.langchain4j.data.message.AiMessage;
+import dev.langchain4j.model.StreamingResponseHandler;
 import dev.langchain4j.model.chat.ChatLanguageModel;
+import dev.langchain4j.model.chat.StreamingChatLanguageModel;
 import dev.langchain4j.model.input.Prompt;
 import dev.langchain4j.model.input.PromptTemplate;
 import dev.langchain4j.model.output.Response;
@@ -24,9 +31,11 @@
  * DataInterpretProcessor interprets query result to make it more readable to the users.
  */
 public class DataInterpretProcessor implements ExecuteResultProcessor {
-
+    public static String tip = "AI 回答中...\r\n";
     private static final Logger keyPipelineLog = LoggerFactory.getLogger("keyPipeline");
 
+    private static Map<Long, StringBuffer> resultCache = new HashMap<>();
+
     public static final String APP_KEY = "DATA_INTERPRETER";
     private static final String INSTRUCTION = ""
             + "#Role: You are a data expert who communicates with business users everyday."
@@ -41,6 +50,16 @@ public DataInterpretProcessor() {
                 .appModule(AppModule.CHAT).description("通过大模型对结果数据做提炼总结").enable(false).build());
     }
 
+    public static String getTextSummary(Long queryId) {
+        if (resultCache.get(queryId) != null) {
+            return resultCache.get(queryId).toString();
+        }
+        return "";
+    }
+
+    public static Map<Long, StringBuffer> getResultCache() {
+        return resultCache;
+    }
 
     @Override
     public boolean accept(ExecuteContext executeContext) {
@@ -71,14 +90,49 @@ public void process(ExecuteContext executeContext) {
         variable.put("data", queryResult.getTextResult());
 
         Prompt prompt = PromptTemplate.from(chatApp.getPrompt()).apply(variable);
-        ChatLanguageModel chatLanguageModel =
-                ModelProvider.getChatModel(chatApp.getChatModelConfig());
-        Response<AiMessage> response = chatLanguageModel.generate(prompt.toUserMessage());
-        String anwser = response.content().text();
-        keyPipelineLog.info("DataInterpretProcessor modelReq:\n{} \nmodelResp:\n{}", prompt.text(),
-                anwser);
-        if (StringUtils.isNotBlank(anwser)) {
-            queryResult.setTextSummary(anwser);
+        if (executeContext.getRequest().isStreamingResult()) {
+            StreamingChatLanguageModel chatLanguageModel =
+                    ModelProvider.getChatStreamingModel(chatApp.getChatModelConfig());
+            final Long queryId = executeContext.getRequest().getQueryId();
+            resultCache.put(queryId, new StringBuffer(tip));
+            chatLanguageModel.generate(prompt.toUserMessage(),
+                    new StreamingResponseHandler<AiMessage>() {
+                        @Override
+                        public void onNext(String token) {
+                            resultCache.get(queryId).append(token);
+                        }
+
+                        @Override
+                        public void onComplete(Response<AiMessage> response) {
+                            ChatQueryRepository chatQueryRepository =
+                                    ContextUtils.getBean(ChatQueryRepository.class);
+                            ChatQueryDO chatQueryDO = chatQueryRepository.getChatQueryDO(queryId);
+                            JSONObject queryResult = JSON.parseObject(chatQueryDO.getQueryResult());
+                            queryResult.put("textSummary",
+                                    resultCache.get(queryId).toString().substring(tip.length()));
+                            chatQueryDO.setQueryResult(queryResult.toJSONString());
+                            chatQueryRepository.updateChatQuery(chatQueryDO);
+                            resultCache.remove(queryId);
+                        }
+
+                        @Override
+                        public void onError(Throwable error) {
+                            error.printStackTrace();
+                            resultCache.remove(queryId);
+                        }
+                    });
+        } else {
+            ChatLanguageModel chatLanguageModel =
+                    ModelProvider.getChatModel(chatApp.getChatModelConfig());
+            Response<AiMessage> response = chatLanguageModel.generate(prompt.toUserMessage());
+            String anwser = response.content().text();
+            keyPipelineLog.info("DataInterpretProcessor modelReq:\n{} \nmodelResp:\n{}",
+                    prompt.text(), anwser);
+            if (StringUtils.isNotBlank(anwser)) {
+                queryResult.setTextSummary(anwser);
+            }
         }
+
+
     }
 }
diff --git a/chat/server/src/main/java/com/tencent/supersonic/chat/server/rest/ChatQueryController.java b/chat/server/src/main/java/com/tencent/supersonic/chat/server/rest/ChatQueryController.java
@@ -5,6 +5,7 @@
 import com.tencent.supersonic.chat.api.pojo.request.ChatParseReq;
 import com.tencent.supersonic.chat.api.pojo.request.ChatQueryDataReq;
 import com.tencent.supersonic.chat.api.pojo.response.ChatParseResp;
+import com.tencent.supersonic.chat.api.pojo.response.QueryResult;
 import com.tencent.supersonic.chat.server.service.ChatQueryService;
 import com.tencent.supersonic.common.pojo.User;
 import com.tencent.supersonic.common.pojo.exception.InvalidArgumentException;
@@ -50,6 +51,14 @@ public Object execute(@RequestBody ChatExecuteReq chatExecuteReq, HttpServletReq
         return chatQueryService.execute(chatExecuteReq);
     }
 
+    @PostMapping("getExecuteSummary")
+    public Object getExecuteSummary(@RequestBody ChatExecuteReq chatExecuteReq,
+            HttpServletRequest request, HttpServletResponse response) {
+        chatExecuteReq.setUser(UserHolder.findUser(request, response));
+        QueryResult res = chatQueryService.getTextSummary(chatExecuteReq);
+        return res;
+    }
+
     @PostMapping("/")
     public Object query(@RequestBody ChatParseReq chatParseReq, HttpServletRequest request,
             HttpServletResponse response) throws Exception {
diff --git a/chat/server/src/main/java/com/tencent/supersonic/chat/server/service/ChatManageService.java b/chat/server/src/main/java/com/tencent/supersonic/chat/server/service/ChatManageService.java
@@ -35,6 +35,8 @@ public interface ChatManageService {
 
     QueryResp getChatQuery(Long queryId);
 
+    ChatQueryDO getChatQueryDO(Long queryId);
+
     List<QueryResp> getChatQueries(Integer chatId);
 
     ShowCaseResp queryShowCase(PageQueryInfoReq pageQueryInfoReq, int agentId);
diff --git a/chat/server/src/main/java/com/tencent/supersonic/chat/server/service/ChatQueryService.java b/chat/server/src/main/java/com/tencent/supersonic/chat/server/service/ChatQueryService.java
@@ -19,6 +19,8 @@ public interface ChatQueryService {
 
     QueryResult execute(ChatExecuteReq chatExecuteReq) throws Exception;
 
+    QueryResult getTextSummary(ChatExecuteReq chatExecuteReq);
+
     QueryResult parseAndExecute(ChatParseReq chatParseReq);
 
     Object queryData(ChatQueryDataReq chatQueryDataReq, User user) throws Exception;
diff --git a/chat/server/src/main/java/com/tencent/supersonic/chat/server/service/impl/ChatManageServiceImpl.java b/chat/server/src/main/java/com/tencent/supersonic/chat/server/service/impl/ChatManageServiceImpl.java
@@ -123,6 +123,11 @@ public QueryResp getChatQuery(Long queryId) {
         return chatQueryRepository.getChatQuery(queryId);
     }
 
+    @Override
+    public ChatQueryDO getChatQueryDO(Long queryId) {
+        return chatQueryRepository.getChatQueryDO(queryId);
+    }
+
     @Override
     public List<QueryResp> getChatQueries(Integer chatId) {
         List<QueryResp> queries = chatQueryRepository.getChatQueries(chatId);
diff --git a/chat/server/src/main/java/com/tencent/supersonic/chat/server/service/impl/ChatQueryServiceImpl.java b/chat/server/src/main/java/com/tencent/supersonic/chat/server/service/impl/ChatQueryServiceImpl.java
@@ -1,5 +1,7 @@
 package com.tencent.supersonic.chat.server.service.impl;
 
+import com.alibaba.fastjson.JSONObject;
+import com.alibaba.fastjson2.JSON;
 import com.google.common.collect.Lists;
 import com.tencent.supersonic.chat.api.pojo.request.ChatExecuteReq;
 import com.tencent.supersonic.chat.api.pojo.request.ChatParseReq;
@@ -9,8 +11,10 @@
 import com.tencent.supersonic.chat.server.agent.Agent;
 import com.tencent.supersonic.chat.server.executor.ChatQueryExecutor;
 import com.tencent.supersonic.chat.server.parser.ChatQueryParser;
+import com.tencent.supersonic.chat.server.persistence.dataobject.ChatQueryDO;
 import com.tencent.supersonic.chat.server.pojo.ExecuteContext;
 import com.tencent.supersonic.chat.server.pojo.ParseContext;
+import com.tencent.supersonic.chat.server.processor.execute.DataInterpretProcessor;
 import com.tencent.supersonic.chat.server.processor.execute.ExecuteResultProcessor;
 import com.tencent.supersonic.chat.server.processor.parse.ParseResultProcessor;
 import com.tencent.supersonic.chat.server.service.AgentService;
@@ -143,6 +147,21 @@ public QueryResult execute(ChatExecuteReq chatExecuteReq) {
         return queryResult;
     }
 
+    @Override
+    public QueryResult getTextSummary(ChatExecuteReq chatExecuteReq) {
+        String text = DataInterpretProcessor.getTextSummary(chatExecuteReq.getQueryId());
+        if (StringUtils.isNotBlank(text)) {
+            QueryResult res = new QueryResult();
+            res.setTextSummary(text);
+            res.setQueryId(chatExecuteReq.getQueryId());
+            return res;
+        } else {
+            ChatQueryDO chatQueryDo = chatManageService.getChatQueryDO(chatExecuteReq.getQueryId());
+            QueryResult res = JSON.parseObject(chatQueryDo.getQueryResult(), QueryResult.class);
+            return res;
+        }
+    }
+
     @Override
     public QueryResult parseAndExecute(ChatParseReq chatParseReq) {
         ChatParseResp parseResp = parse(chatParseReq);
diff --git a/chat/server/src/main/java/com/tencent/supersonic/chat/server/service/impl/PluginServiceImpl.java b/chat/server/src/main/java/com/tencent/supersonic/chat/server/service/impl/PluginServiceImpl.java
@@ -108,6 +108,7 @@ public List<ChatPlugin> query(PluginQueryReq pluginQueryReq) {
         if (StringUtils.isNotBlank(pluginQueryReq.getCreatedBy())) {
             queryWrapper.lambda().eq(PluginDO::getCreatedBy, pluginQueryReq.getCreatedBy());
         }
+        queryWrapper.orderByAsc("name");
         List<PluginDO> pluginDOS = pluginRepository.query(queryWrapper);
         if (StringUtils.isNotBlank(pluginQueryReq.getPattern())) {
             pluginDOS = pluginDOS.stream()
diff --git a/common/src/main/java/com/tencent/supersonic/common/service/impl/SystemConfigServiceImpl.java b/common/src/main/java/com/tencent/supersonic/common/service/impl/SystemConfigServiceImpl.java
@@ -16,6 +16,7 @@
 
 import java.util.List;
 import java.util.concurrent.atomic.AtomicReference;
+import java.util.stream.Collectors;
 
 @Service
 public class SystemConfigServiceImpl extends ServiceImpl<SystemConfigMapper, SystemConfigDO>
@@ -38,8 +39,8 @@ public SystemConfig getSystemConfig() {
         return systemConfigDb;
     }
 
-    private SystemConfig getSystemConfigFromDB() {
-        List<SystemConfigDO> list = list();
+    private SystemConfig getSystemConfigFromDB() { // 加上id ，如果有多条记录，会出错
+        List<SystemConfigDO> list = this.lambdaQuery().eq(SystemConfigDO::getId, 1).list();
         if (CollectionUtils.isEmpty(list)) {
             SystemConfig systemConfig = new SystemConfig();
             systemConfig.setId(1);
diff --git a/common/src/main/java/dev/langchain4j/provider/DifyModelFactory.java b/common/src/main/java/dev/langchain4j/provider/DifyModelFactory.java
@@ -7,6 +7,7 @@
 import dev.langchain4j.model.dify.DifyAiChatModel;
 import dev.langchain4j.model.embedding.EmbeddingModel;
 import dev.langchain4j.model.openai.OpenAiEmbeddingModel;
+import dev.langchain4j.model.openai.OpenAiStreamingChatModel;
 import org.springframework.beans.factory.InitializingBean;
 import org.springframework.stereotype.Service;
 
@@ -25,6 +26,11 @@ public ChatLanguageModel createChatModel(ChatModelConfig modelConfig) {
                 .modelName(modelConfig.getModelName()).timeOut(modelConfig.getTimeOut()).build();
     }
 
+    @Override
+    public OpenAiStreamingChatModel createChatStreamingModel(ChatModelConfig modelConfig) {
+        throw new RuntimeException("待开发");
+    }
+
     @Override
     public EmbeddingModel createEmbeddingModel(EmbeddingModelConfig embeddingModelConfig) {
         return OpenAiEmbeddingModel.builder().baseUrl(embeddingModelConfig.getBaseUrl())
diff --git a/common/src/main/java/dev/langchain4j/provider/InMemoryModelFactory.java b/common/src/main/java/dev/langchain4j/provider/InMemoryModelFactory.java
@@ -5,6 +5,7 @@
 import dev.langchain4j.model.chat.ChatLanguageModel;
 import dev.langchain4j.model.embedding.EmbeddingModel;
 import dev.langchain4j.model.embedding.S2OnnxEmbeddingModel;
+import dev.langchain4j.model.openai.OpenAiStreamingChatModel;
 import org.apache.commons.lang3.StringUtils;
 import org.springframework.beans.factory.InitializingBean;
 import org.springframework.stereotype.Service;
@@ -35,6 +36,11 @@ public EmbeddingModel createEmbeddingModel(EmbeddingModelConfig embeddingModel)
         return EmbeddingModelConstant.BGE_SMALL_ZH_MODEL;
     }
 
+    @Override
+    public OpenAiStreamingChatModel createChatStreamingModel(ChatModelConfig modelConfig) {
+        throw new RuntimeException("待开发");
+    }
+
     @Override
     public void afterPropertiesSet() {
         ModelProvider.add(PROVIDER, this);
diff --git a/common/src/main/java/dev/langchain4j/provider/LocalAiModelFactory.java b/common/src/main/java/dev/langchain4j/provider/LocalAiModelFactory.java
@@ -6,6 +6,7 @@
 import dev.langchain4j.model.embedding.EmbeddingModel;
 import dev.langchain4j.model.localai.LocalAiChatModel;
 import dev.langchain4j.model.localai.LocalAiEmbeddingModel;
+import dev.langchain4j.model.openai.OpenAiStreamingChatModel;
 import org.springframework.beans.factory.InitializingBean;
 import org.springframework.stereotype.Service;
 
@@ -27,6 +28,11 @@ public ChatLanguageModel createChatModel(ChatModelConfig modelConfig) {
                 .build();
     }
 
+    @Override
+    public OpenAiStreamingChatModel createChatStreamingModel(ChatModelConfig modelConfig) {
+        throw new RuntimeException("待开发");
+    }
+
     @Override
     public EmbeddingModel createEmbeddingModel(EmbeddingModelConfig embeddingModel) {
         return LocalAiEmbeddingModel.builder().baseUrl(embeddingModel.getBaseUrl())
diff --git a/common/src/main/java/dev/langchain4j/provider/ModelFactory.java b/common/src/main/java/dev/langchain4j/provider/ModelFactory.java
@@ -4,9 +4,12 @@
 import com.tencent.supersonic.common.pojo.EmbeddingModelConfig;
 import dev.langchain4j.model.chat.ChatLanguageModel;
 import dev.langchain4j.model.embedding.EmbeddingModel;
+import dev.langchain4j.model.openai.OpenAiStreamingChatModel;
 
 public interface ModelFactory {
     ChatLanguageModel createChatModel(ChatModelConfig modelConfig);
 
+    OpenAiStreamingChatModel createChatStreamingModel(ChatModelConfig modelConfig);
+
     EmbeddingModel createEmbeddingModel(EmbeddingModelConfig embeddingModel);
 }
diff --git a/common/src/main/java/dev/langchain4j/provider/ModelProvider.java b/common/src/main/java/dev/langchain4j/provider/ModelProvider.java
@@ -5,7 +5,9 @@
 import com.tencent.supersonic.common.pojo.EmbeddingModelConfig;
 import com.tencent.supersonic.common.util.ContextUtils;
 import dev.langchain4j.model.chat.ChatLanguageModel;
+import dev.langchain4j.model.chat.StreamingChatLanguageModel;
 import dev.langchain4j.model.embedding.EmbeddingModel;
+import dev.langchain4j.model.openai.OpenAiStreamingChatModel;
 import org.apache.commons.lang3.StringUtils;
 
 import java.util.HashMap;
@@ -41,6 +43,20 @@ public static ChatLanguageModel getChatModel(ChatModelConfig modelConfig) {
                 "Unsupported ChatLanguageModel provider: " + modelConfig.getProvider());
     }
 
+    public static StreamingChatLanguageModel getChatStreamingModel(ChatModelConfig modelConfig) {
+        if (modelConfig == null || StringUtils.isBlank(modelConfig.getProvider())
+                || StringUtils.isBlank(modelConfig.getBaseUrl())) {
+            modelConfig = DEMO_CHAT_MODEL;
+        }
+        ModelFactory modelFactory = factories.get(modelConfig.getProvider().toUpperCase());
+        if (modelFactory != null) {
+            return modelFactory.createChatStreamingModel(modelConfig);
+        }
+
+        throw new RuntimeException(
+                "Unsupported ChatLanguageModel provider: " + modelConfig.getProvider());
+    }
+
     public static EmbeddingModel getEmbeddingModel() {
         return getEmbeddingModel(null);
     }
diff --git a/common/src/main/java/dev/langchain4j/provider/OllamaModelFactory.java b/common/src/main/java/dev/langchain4j/provider/OllamaModelFactory.java
@@ -6,6 +6,7 @@
 import dev.langchain4j.model.embedding.EmbeddingModel;
 import dev.langchain4j.model.ollama.OllamaChatModel;
 import dev.langchain4j.model.ollama.OllamaEmbeddingModel;
+import dev.langchain4j.model.openai.OpenAiStreamingChatModel;
 import org.springframework.beans.factory.InitializingBean;
 import org.springframework.stereotype.Service;
 
@@ -28,6 +29,11 @@ public ChatLanguageModel createChatModel(ChatModelConfig modelConfig) {
                 .logResponses(modelConfig.getLogResponses()).build();
     }
 
+    @Override
+    public OpenAiStreamingChatModel createChatStreamingModel(ChatModelConfig modelConfig) {
+        throw new RuntimeException("待开发");
+    }
+
     @Override
     public EmbeddingModel createEmbeddingModel(EmbeddingModelConfig embeddingModelConfig) {
         return OllamaEmbeddingModel.builder().baseUrl(embeddingModelConfig.getBaseUrl())
diff --git a/common/src/main/java/dev/langchain4j/provider/OpenAiModelFactory.java b/common/src/main/java/dev/langchain4j/provider/OpenAiModelFactory.java
diff --git a/headless/chat/src/main/java/com/tencent/supersonic/headless/chat/knowledge/MultiCustomDictionary.java b/headless/chat/src/main/java/com/tencent/supersonic/headless/chat/knowledge/MultiCustomDictionary.java
diff --git a/webapp/packages/chat-sdk/src/components/ChatItem/index.tsx b/webapp/packages/chat-sdk/src/components/ChatItem/index.tsx
diff --git a/webapp/packages/chat-sdk/src/service/index.ts b/webapp/packages/chat-sdk/src/service/index.ts

Original file line number	Diff line number	Diff line change
`@@ -18,4 +18,5 @@ public class ChatExecuteReq {`
`18`	`18`	`private int parseId;`
`19`	`19`	`private String queryText;`
`20`	`20`	`private boolean saveAnswer;`
	`21`	`+ private boolean streamingResult;`
`21`	`22`	`}`
Original file line number	Diff line number	Diff line change
`@@ -108,6 +108,7 @@ public List<ChatPlugin> query(PluginQueryReq pluginQueryReq) {`
`108`	`108`	`if (StringUtils.isNotBlank(pluginQueryReq.getCreatedBy())) {`
`109`	`109`	`queryWrapper.lambda().eq(PluginDO::getCreatedBy, pluginQueryReq.getCreatedBy());`
`110`	`110`	`}`
	`111`	`+ queryWrapper.orderByAsc("name");`
`111`	`112`	`List<PluginDO> pluginDOS = pluginRepository.query(queryWrapper);`
`112`	`113`	`if (StringUtils.isNotBlank(pluginQueryReq.getPattern())) {`
`113`	`114`	`pluginDOS = pluginDOS.stream()`