Add support for adding PHP extensions

node_modules/lodash/_castFunction.js

@@ -1,14 +0,0 @@
-var identity = require('./identity');
-
-/**
- * Casts `value` to `identity` if it's not a function.
- *
- * @private
- * @param {*} value The value to inspect.
- * @returns {Function} Returns cast function.
- */
-function castFunction(value) {
-  return typeof value == 'function' ? value : identity;
-}
-
-module.exports = castFunction;