fix: PaperListResultItem no longer implements Stringer

Author: kkweon

Diff for: models/paper_list_result.go

@@ -1,7 +1,5 @@
 package models
 
-import "fmt"
-
 // PaperListResult is the result of PaperListResult() function.
 type PaperListResult struct {
 	Count    int64                 `json:"count"`
@@ -10,8 +8,6 @@ type PaperListResult struct {
 	Results  []PaperListResultItem `json:"results"`
 }
 
-var _ fmt.Stringer = (*PaperListResultItem)(nil)
-
 type PaperListResultItem struct {
 	ID               string         `json:"id"`
 	ArxivID          *string        `json:"arxiv_id"`
@@ -26,4 +22,4 @@ type PaperListResultItem struct {
 	ConferenceURLAbs *string        `json:"conference_url_abs"`
 	ConferenceURLPDF *string        `json:"conference_url_pdf"`
 	Proceeding       *string        `json:"proceeding"`
-}
+}