Function identity

lib/assets/react-source/development/react.js:29234–29236

(fn)

	// Helper function to allow the creation of anonymous functions which do not
	// have .name set to the name of the variable being assigned to.
	function identity(fn) {
	  return fn;
	}

	var ReactPropTypeLocationNames;
	if (process.env.NODE_ENV !== 'production') {