def payload_element_name(element_name):
def decorator(klass):<EOL><INDENT>"""<STR_LIT>"""<EOL>from .stanzapayload import STANZA_PAYLOAD_CLASSES<EOL>from .stanzapayload import STANZA_PAYLOAD_ELEMENTS<EOL>if hasattr(klass, "<STR_LIT>"):<EOL><INDENT>klass._pyxmpp_payload_element_name.append(element_name)<EOL><DEDENT>else:<EOL><INDENT>klass._pyxmpp_payload_element_name = [element_name]<EOL><DEDENT>if element_name in STANZA_PAYLOAD_CLASSES:<EOL><INDENT>logger = logging.getLogger('<STR_LIT>')<EOL>logger.warning("<STR_LIT>".format(<EOL>element_name))<EOL><DEDENT>STANZA_PAYLOAD_CLASSES[element_name] = klass<EOL>STANZA_PAYLOAD_ELEMENTS[klass].append(element_name)<EOL>return klass<EOL><DEDENT>return decorator<EOL>
Class decorator generator for decorationg
    `StanzaPayload` subclasses.

    :Parameters:
        - `element_name`: XML element qname handled by the class
    :Types:
        - `element_name`: `unicode`