'Test if the address is unspecified.
Returns:
A boolean, True if this is the unspecified address as defined in
RFC 5735 3.'

@property
def is_unspecified(self):

    unspecified_address = IPv4Address('0.0.0.0')
    if isinstance(self, _BaseAddress):
        return (self in unspecified_address)
    return (self.network_address == self.broadcast_address == unspecified_address)
