code: function _gpfDefClassAttrFilter (attributes, baseAttributeClass) {
      if (baseAttributeClass) {
          return attributes.filter(function (attribute) {
              return attribute instanceof baseAttributeClass;
          });
      }
      return attributes;
  }
docs: /*global _GPF_DEFINE_CLASS_ATTRIBUTES_NAME $attributes /*global _GpfClassDefinition Class definition /*global _gpfArrayForEach Almost like [].forEach (undefined are also enumerated) /*global _gpfObjectForEach Similar to [].forEach but for objects /*#endif