'Initialize with a private or public
C{cryptography.hazmat.primitives.asymmetric} key.
@param keyObject: Low level key.
@type keyObject: C{cryptography.hazmat.primitives.asymmetric} key.'

def __init__(self, keyObject):

    if keyObject.__class__.__module__.startswith('Crypto.PublicKey'):
        warningString = getDeprecationWarningString(Key, Version('Twisted', 16, 0, 0), replacement='passing    a    cryptography    key    object')
        warnings.warn(warningString, DeprecationWarning, stacklevel=2)
        self.keyObject = keyObject
    else:
        self._keyObject = keyObject
