Create a key object by reading a private key from a file (or file-like)
        object.  If the private key is encrypted and ``password`` is not
        ``None``, the given password will be used to decrypt the key (otherwise
        `.PasswordRequiredException` is thrown).

        :param file_obj: the file-like object to read from
        :param str password:
            an optional password to use to decrypt the key, if it's encrypted
        :return: a new `.PKey` based on the given private key

        :raises: ``IOError`` -- if there was an error reading the key
        :raises: `.PasswordRequiredException` --
            if the private key file is encrypted, and ``password`` is ``None``
        :raises: `.SSHException` -- if the key file is invalid

def from_private_key(cls, file_obj, password=None):
        """
        Create a key object by reading a private key from a file (or file-like)
        object.  If the private key is encrypted and ``password`` is not
        ``None``, the given password will be used to decrypt the key (otherwise
        `.PasswordRequiredException` is thrown).

        :param file_obj: the file-like object to read from
        :param str password:
            an optional password to use to decrypt the key, if it's encrypted
        :return: a new `.PKey` based on the given private key

        :raises: ``IOError`` -- if there was an error reading the key
        :raises: `.PasswordRequiredException` --
            if the private key file is encrypted, and ``password`` is ``None``
        :raises: `.SSHException` -- if the key file is invalid
        """
        key = cls(file_obj=file_obj, password=password)
        return key