import Foundation

extension ModelList
{
    func searchItems(forInput:String) -> [ModelListItem]
    {
        let cleanedInput:String = cleanInput(input:forInput)
        let countCharacters:Int = cleanedInput.characters.count
        let items:[ModelListItem]
        
        if countCharacters > 0
        {
            items = []
        }
        else
        {
            items = self.items
        }
        
        return items
    }
    
    //MARK: private
    
    private func cleanInput(input:String) -> String
    {
        let cleaned:String = input
        
        return cleaned
    }
}

import Foundation

extension ModelList
{
    func searchItems(forInput:String) -> [ModelListItem]
    {
        let cleanedInput:String = cleanInput(input:forInput)
        
        return []
    }
    
    //MARK: private
    
    private func cleanInput(input:String) -> String
    {
        let cleaned:String = input
        
        return cleaned
    }
}

--- 
+++ 
@@ -5,8 +5,19 @@
     func searchItems(forInput:String) -> [ModelListItem]
     {
         let cleanedInput:String = cleanInput(input:forInput)
+        let countCharacters:Int = cleanedInput.characters.count
+        let items:[ModelListItem]
         
-        return []
+        if countCharacters > 0
+        {
+            items = []
+        }
+        else
+        {
+            items = self.items
+        }
+        
+        return items
     }
     
     //MARK: private
Return items when search is empty
