def merge_element!(hash, element, depth)
        raise "Document too deep!" if depth == 0
        delete_empty(hash)
        merge!(hash, element.tag_name, collapse(element, depth))
      end
def merge_element!(hash, element, depth)
        raise "Document too deep!" if depth == 0
        delete_empty(hash)
        merge!(hash, element.tag_name, collapse(element, depth))
      end
Convert an XML element and merge into the hash

 hash::
   Hash to merge the converted element into.
 element::
   XML element to merge into hash