         }
 
         let existingRows: [T] = self.rowsBySectionID[inSectionID] ?? []
-
         var newRows: [T] = existingRows
 
-        let newIdentifiers = rowsToUpdate.map({ (inDataSourceItem) -> String in
-            return inDataSourceItem.identifier
-        })
-        let existingIdentifiers = existingRows.map({ (inDataSourceItem) -> String in
-            return inDataSourceItem.identifier
-        })
+        let newIdentifiers = rowsToUpdate.map { $0.identifier }
+        let existingIdentifiers = existingRows.map { $0.identifier }
 
         let diffs = diffBetweenArrays(arrayA: existingIdentifiers, arrayB: newIdentifiers)
 

            case .insert:
                for rowID in diff.array {
                    // find index of new row
                    let findBlock = { (inDataSourceItem: T) -> Bool in
                        return rowID == inDataSourceItem.identifier
                    }

                    let rowIDIndex = rowsToUpdate.index(where: findBlock)
                    if let actualIndex = rowIDIndex {
                        let newRow = rowsToUpdate[actualIndex]
                        newRows.insert(newRow, at: rowIndex)

// swiftlint:disable function_body_length
// swiftlint:disable line_length

//
