class Nokogiri::XML::Node

def before(node_or_tags)

Also see related method +add_previous_sibling+.

Returns +self+, to support chaining of calls.

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

Insert +node_or_tags+ before this node (as a sibling).
### 
def before(node_or_tags)
  add_previous_sibling(node_or_tags)
  self
end