code: def emit_stanza(self, element):
          Serialize a stanza.
  
          Must be called after `emit_head`.
  
          :Parameters:
              - `element`: the element to serialize
          :Types:
              - `element`: :etree:`ElementTree.Element`
  
          :Return: serialized element
          :Returntype: `unicode`
          """
          if not self._head_emitted:
              raise RuntimeError(".emit_head() must be called first.")
          string = self._emit_element(element, level = 1,
                                      declared_prefixes = self._root_prefixes)
          return remove_evil_characters(string)
docs: Serialize a stanza.
  
          Must be called after `emit_head`.
  
          :Parameters:
              - `element`: the element to serialize
          :Types:
              - `element`: :etree:`ElementTree.Element`
  
          :Return: serialized element
          :Returntype: `unicode`