docs: function _queryInterface (interfaceDefinition) {
      /*jshint validthis:true*/ // Called with apply
      var
          array = (new gpf.attributes.Map(this))
              .getMemberAttributes("Class")
              .filter(gpf.attributes.InterfaceImplementAttribute),
          builder;
      if (!array.every(function (attribute) {
          builder = attribute._builder;
          return attribute._interfaceDefinition !== interfaceDefinition || !builder;
      })) {
          if ("function" === typeof builder) {
              return builder(this);
          }
          // Expects a member name
          return this[builder]();
      }
      // Otherwise
      return null;
  }