code: function updateFold(fold, offset){
  			var next = fold;
  			var parentFold = THIS.parentFold;
  			
  			while(next = next.nextFold)
  				next.y  += offset;
  			parentFold || edgeCheck(offset);
  			fold.height += offset;
  			THIS.height += offset;
  			
  			parentFold && parentFold.open && THIS.parent.updateFold(parentFold, offset);
  		}
docs: Update the vertical ordinate of each sibling for a particular fold.
  
  @param {Fold} fold
  @param {Number} offset - Pixel distance to adjust by