code: function ( node ) {
        this.__class__ = 'HaveProperty';
        this.node = node;
  
        this.validate = function ( object ) {
          if ( 'undefined' === typeof object[ this.node ] )
            throw new Violation( this, object, { value: this.node } );
  
          return true;
        };
  
        return this;
      }
docs: Asserts definitions