code: protected final void setLeftMessage(@Nullable final CharSequence message,
                                          @Nullable final Drawable icon, final boolean error) {
          if (message != null) {
              leftMessage.setText(message);
              leftMessage.setCompoundDrawablesWithIntrinsicBounds(icon, null, null, null);
              leftMessage.setTextColor(error ? getErrorColor() : getHelperTextColor());
              leftMessage.setTag(error);
              leftMessage.setVisibility(View.VISIBLE);
          } else if (getHelperText() != null) {
              setLeftMessage(getHelperText(), null, false);
          } else {
              leftMessage.setTag(false);
              leftMessage.setVisibility(View.GONE);
          }
      }
docs: Shows a specific message at the left edge of the view.
  
  @param message
  The message, which should be shown, as an instance of the type {@link CharSequence}
  or null, if no message should be shown
  @param icon
  The icon, which should be shown, as an instance of the type {@link Drawable} or null,
  if no icon should be shown
  @param error
  True, if the message should be highlighted as an error, false otherwise