code: function extractSetterFromNode( handler, node ) {
  
  	assignSetterFnForNode( handler, node );
  
  	if ( node.children ) {
  		// Recurse down to this node's children
  		Object.keys( node.children ).forEach( ( key ) => {
  			extractSetterFromNode( handler, node.children[ key ] );
  		} );
  	}
  }
docs: Walk the tree of a specific resource node to create the setter methods
  
  The API we want to produce from the node tree looks like this:
  
  wp.posts();                        /wp/v2/posts
  wp.posts().id( 7 );                /wp/v2/posts/7
  wp.posts().id( 7 ).revisions();    /wp/v2/posts/7/revisions
  wp.posts().id( 7 ).revisions( 8 ); /wp/v2/posts/7/revisions/8
  
  ^ That last one's the tricky one: we can deduce that this parameter is "id", but
  that param will already be taken by the post ID, so sub-collections have to be
  set up as `.revisions()` to get the collection, and `.revisions( id )` to get a
  specific resource.
  
  @private
  @param  {Object} node            A node object
  @param  {Object} [node.children] An object of child nodes
  // @returns {isLeaf} A boolean indicating whether the processed node is a leaf