code: public ApnsPayloadBuilder setAlertBody(final String alertBody) {
          this.alertBody = alertBody;
  
          this.localizedAlertKey = null;
          this.localizedAlertArguments = null;
  
          return this;
      }
docs: <p>Sets the literal text of the alert message to be shown for the push notification. Clears any previously-set
  localized alert message key and arguments.</p>
  
  <p>By default, no message is shown.</p>
  
  @param alertBody the literal message to be shown for this push notification
  
  @return a reference to this payload builder
  
  @see ApnsPayloadBuilder#setLocalizedAlertMessage(String, String...)