class Nokogiri::XML::Node

def prepend_child(node_or_tags)

Also see related method +add_child+.

a DocumentFragment, NodeSet, or String).
Returns the reparented node (if +node_or_tags+ is a Node), or NodeSet (if +node_or_tags+ is

containing markup.
+node_or_tags+ can be a Nokogiri::XML::Node, a ::DocumentFragment, a ::NodeSet, or a String

Add +node_or_tags+ as the first child of this Node.
## 
def prepend_child(node_or_tags)
  if (first = children.first)
    # Mimic the error add_child would raise.
    raise "Document already has a root node" if document? && !(node_or_tags.comment? || node_or_tags.processing_instruction?)
    first.__send__(:add_sibling, :previous, node_or_tags)
  else
    add_child(node_or_tags)
  end
end