code: function extendCtx(context, parentContext) {
  		// Return copy of parentContext, unless context is defined and is different, in which case return a new merged context
  		// If neither context nor parentContext are undefined, return undefined
  		return context && context !== parentContext
  			? (parentContext
  				? $extend($extend({}, parentContext), context)
  				: context)
  			: parentContext && $extend({}, parentContext);
  	}
docs: ========== Utilities ========== Merge objects, in particular contexts which inherit from parent contexts