function Identifier( node, parents ) {
		var locals;
		var name;
		var i;

		name = node.name;
		if ( name === 'undefined' ) {
			return;
		}
		for ( i = 0; i < parents.length; i++ ) {
			if ( name === 'arguments' && declaresArguments( parents[ i ] ) ) {
				return;
			}
			locals = parents[ i ].locals;
			if ( locals && contains( locals.length, locals, 1, 0, name ) ) {
				return;
			}
		}
		appendUnique( globals, name );
	}
Callback invoked upon encountering an identifier AST node.

@private
@param {Node} node - AST node
@param {Array} parents - array of parent AST nodes