code: protected void performFiltering(CharSequence text, int keyCode) {
          switch (mAutoCompleteMode){
              case AUTOCOMPLETE_MODE_SINGLE:
                  ((InternalAutoCompleteTextView)mInputView).superPerformFiltering(text, keyCode);
                  break;
              case AUTOCOMPLETE_MODE_MULTI:
                  ((InternalMultiAutoCompleteTextView)mInputView).superPerformFiltering(text, keyCode);
                  break;
          }
      }
docs: <p>Starts filtering the content of the drop down list. The filtering
  pattern is the content of the edit box. Subclasses should override this
  method to filter with a different pattern, for instance a substring of
  <code>text</code>.</p>
  
  @param text the filtering pattern
  @param keyCode the last character inserted in the edit box; beware that
  this will be null when text is being added through a soft input method.