code: def find_first(self, name=None, ns_uri=None):
          
          return self.find(name=name, ns_uri=ns_uri, first_only=True)
docs: Find the first :class:`Element` node descendant of this node that
          matches any optional constraints, or None if there are no matching
          elements.
  
          Delegates to :meth:`find` with ``first_only=True``.