code: function flattenNodes(nodes) {
  	return nodes.reduce((acc, item) => {
  		if (item.nodes) acc.push(...flattenNodes(item.nodes))
  		else acc.push(item);
  		return acc;
  	}, []);
  }
docs: Flattens `expr.nodes` array and returns it (the flattened array, not the `expr`).
  
  @param  {StylusObject} expr
  @return {Array}