class REXML::Child

def next_sibling=( other )

# =>
b.next_sibling = c
c = Element.new("c")
b = a.add_element("b")
a = Element.new("a")
after some other child.
Sets the next sibling of this child. This can be used to insert a child 
def next_sibling=( other )
  parent.insert_after self, other
end