def __init__(self, msg=None, data=None):
pass<EOL>
Create a new instance of this public key type.  If ``msg`` is given,
the key's public part(s) will be filled in from the message.  If
``data`` is given, the key's public part(s) will be filled in from
the string.

:param .Message msg:
    an optional SSH `.Message` containing a public key of this type.
:param str data: an optional string containing a public key
    of this type

:raises: `.SSHException` --
    if a key cannot be created from the ``data`` or ``msg`` given, or
    no key was passed in.