def __init__(self, **props):
d = {}<EOL>for propname, _ in self.PROPERTIES:<EOL><INDENT>if propname in props:<EOL><INDENT>d[propname] = props[propname]<EOL><DEDENT><DEDENT>self.properties = d<EOL>
Save the properties appropriate to this AMQP content type
        in a 'properties' dictionary.