code: function() {
              var orientation = this.getTreeConfig().rootOrientation;
  
              if ( this.pseudo ) {
                  // prevents separating the subtrees
                  return ( -this.getTreeConfig().subTeeSeparation );
              }
  
              if ( orientation === 'NORTH' || orientation === 'SOUTH' ) {
                  return this.width;
              }
              else if ( orientation === 'WEST' || orientation === 'EAST' ) {
                  return this.height;
              }
          }
docs: Returns the width of the node
  @returns {float}