addChain( node ) {

		/*
		if ( this.chaining.indexOf( node ) !== - 1 ) {

			console.warn( 'Recursive node: ', node );

		}
		*/

		this.chaining.push( node );

	}
Adds the given node to the internal node chain.
This is used to check recursive calls in node-graph.

@param {Node} node - The node to add.