* Check if a variable is a string.

* Mix properties into target object.

* When there are multiple locations for a value pass them all in, then get the * first value that is valid.

* The <strong><code>defineProperty()</code></strong> function provides a * shortcut to defining a property that cannot be accidentally iterated acr

* Make a map and return a function for checking if a key * is in that map.

* Used to register a normalization. This should never be called by users * directly, instead it should be called via an action:<br/> * <code>Vel