code: private OnFocusChangeListener createFocusChangeListener() {
          return new OnFocusChangeListener() {
  
              @Override
              public final void onFocusChange(final View view, final boolean hasFocus) {
                  if (!hasFocus && isValidatedOnFocusLost()) {
                      validate();
                  }
              }
  
          };
      }
docs: Creates and returns a listener, which allows to validate the value of the view, when the view
  loses its focus.
  
  @return The listener, which has been created, as an instance of the type {@link
  OnFocusChangeListener}