'Initialize an empty simple registration request'

def __init__(self, required=None, optional=None, policy_url=None, sreg_ns_uri=ns_uri):

    Extension.__init__(self)
    self.required = []
    self.optional = []
    self.policy_url = policy_url
    self.ns_uri = sreg_ns_uri
    if required:
        self.requestFields(required, required=True, strict=True)
    if optional:
        self.requestFields(optional, required=False, strict=True)
