- * @param {Object} masterVariable
- * @param {Array} objectPathArray
- * @param {Function} injectFn
+ * @param {Object} obj The object into which `injectFn` will be inserted
+ * @param {Array} key The key by which `injectFn` will be known in `obj`; if this already
+ * exists, a wrapper will first call `injectFn` and then the original `obj[key]` function.
+ * @param {Function} injectFn The function to insert