'Provides the address represented by our mask. This is **None** if our
address type is a wildcard.
:param bool cache: caches the result if **True**
:returns: str of our subnet mask for the address (ex. \'255.255.255.0\')'

def get_mask(self, cache=True):

    if (not self._mask):
        address_type = self.get_address_type()
        if (address_type == AddressType.WILDCARD):
            mask = None
        elif (address_type == AddressType.IPv4):
            mask = stem.util.connection.get_mask_ipv4(self._masked_bits)
        elif (address_type == AddressType.IPv6):
            mask = stem.util.connection.get_mask_ipv6(self._masked_bits)
        if (not cache):
            return mask
        self._mask = mask
    return self._mask
