'Create a new L{DomainWithDefaultDict} with the specified keys.
@type keys: iterable of L{bytes}
@param keys: Domain names to serve as keys in the new dictionary.
@type value: L{None} or L{IDomain} provider
@param value: A domain object to serve as the value for all new keys
in the dictionary.
@rtype: L{DomainWithDefaultDict}
@return: A new dictionary.'

def fromkeys(klass, keys, value=None):

    d = klass()
    for k in keys:
        d[k] = value
    return d
