Unable to load Suggested values in Input Control

Hi All,

     I am facing problem while showing suggested values to sap.m.input control. Here is my logic

View

<Input id="ddlCustomer" type="Text"

  placeholder="Enter Customer ..."

  showSuggestion="true"

  StartSuggestion="3"

  suggest="handleSuggest_Customer"

  suggestionItems="{/Customers}">

       <suggestionItems>

            <core:Item

                 key="{CustomerId}"

                 text="{parts:[{path: 'CustomerId' },{path: 'Name' }],

                      formatter: 'sap.ui.demo.myFiori.util.Formatter.CustomerInfo'}"

            />

       </suggestionItems>

</Input>

Formatter Function

CustomerInfo : function(val1, val2) {

  debugger;

  if (val1 != "undefined" && val2 != "undefined") {

  // return val2 + " | " + val1;

  return val1;

  }

Controller