get messageBody() {
    // Returns the *first* message body. Only one should be defined according
    // to the spec, but it's possible to include more.
    return this.filter(item => item.element === 'asset' && item.classes.includes('messageBody')).first;
  }
/**
   * @name messageBody
   * @type Asset
   * @memberof HttpMessagePayload.prototype
   */
@name messageBody
@type Asset
@memberof HttpMessagePayload.prototype
@name messageBody @type Asset @memberof HttpMessagePayload . prototype
get messageBody() {
    return this.filter(item => item.element === 'asset' && item.classes.includes('messageBody')).first;
  }
get messageBody ( ) { return this . filter ( item => item . element === 'asset' && item . classes . includes ( 'messageBody' ) ) . first ; }
@name messageBody
 @type Asset
 @memberof HttpMessagePayload.prototype
@name messageBody @type Asset @memberof HttpMessagePayload . prototype
// Returns the *first* message body. Only one should be defined according // to the spec, but it's possible to include more.