code: protected CharSequence convertSelectionToString(Object selectedItem) {
          switch (mAutoCompleteMode){
              case AUTOCOMPLETE_MODE_SINGLE:
                  return ((InternalAutoCompleteTextView)mInputView).superConvertSelectionToString(selectedItem);
              case AUTOCOMPLETE_MODE_MULTI:
                  return ((InternalMultiAutoCompleteTextView)mInputView).superConvertSelectionToString(selectedItem);
              default:
                  return null;
          }
      }
docs: <p>Converts the selected item from the drop down list into a sequence
  of character that can be used in the edit box.</p>
  
  @param selectedItem the item selected by the user for completion
  
  @return a sequence of characters representing the selected suggestion