function validateTypeDef(Constructor, typeDef, location) {
	  for (var propName in typeDef) {
	    if (typeDef.hasOwnProperty(propName)) {
	      // use a warning instead of an invariant so components
	      // don't show up in prod but only in __DEV__
	      process.env.NODE_ENV !== 'production' ? warning(typeof typeDef[propName] === 'function', '%s: %s type `%s` is invalid; it must be a function, usually from ' + 'React.PropTypes.', Constructor.displayName || 'ReactClass', ReactPropTypeLocationNames[location], propName) : void 0;
	    }
	  }
	}
Special case getDefaultProps which should move into statics but requires
automatic merging.