added special check for function types in debug mode

Author: Jolanrensen

core/src/main/kotlin/org/jetbrains/kotlinx/dataframe/impl/columns/DataColumnImpl.kt

@@ -9,6 +9,8 @@ import org.jetbrains.kotlinx.dataframe.kind
 import kotlin.reflect.KClass
 import kotlin.reflect.KType
 import kotlin.reflect.full.isSubclassOf
+import kotlin.reflect.full.isSubtypeOf
+import kotlin.reflect.typeOf
 
 internal abstract class DataColumnImpl<T>(
     protected val values: List<T>,
@@ -22,6 +24,9 @@ internal abstract class DataColumnImpl<T>(
         when {
             this == null -> type.isMarkedNullable
 
+            // special case since functions are often stored as a $$Lambda$... class, the subClassOf check would fail
+            this is Function<*> && type.isSubtypeOf(typeOf<Function<*>?>()) -> true
+
             this.isPrimitiveArray ->
                 type.isPrimitiveArray &&
                     this!!::class.qualifiedName == type.classifier?.let { (it as KClass<*>).qualifiedName }