code: public final CharSequence getError() {
          if (leftMessage.getVisibility() == View.VISIBLE && (Boolean) leftMessage.getTag()) {
              return leftMessage.getText();
          }
  
          return null;
      }
docs: Returns the error message, which has been previously set to be displayed.
  
  @return The error message, which has been previously set to be displayed, as an instance of
  the type {@link CharSequence} or null, if no error has been set or if it has already been
  cleared by the widget