class REXML::Element

def next_element


d.root.elements['c'].next_element #-> nil
d.root.elements['b'].next_element #->
d = REXML::Document.new 'text'

+niL+ otherwise:
Returns the next sibling that is an element if it exists,

next_element
:call-seq: 
def next_element
  element = next_sibling
  element = element.next_sibling until element.nil? or element.kind_of? Element
  return element
end