@classmethod<EOL><INDENT>def _authorization_header(cls, credentials):<DEDENT>
if cls._x_use_authorization_header:<EOL><INDENT>res = '<STR_LIT::>'.join(<EOL>(credentials.consumer_key,<EOL>credentials.consumer_secret))<EOL>res = base64.b64encode(six.b(res)).decode()<EOL>return {'<STR_LIT>': '<STR_LIT>'.format(res)}<EOL><DEDENT>else:<EOL><INDENT>return {}<EOL><DEDENT>
Creates authorization headers if the provider supports it. See:
http://en.wikipedia.org/wiki/Basic_access_authentication.

:param credentials:
    :class:`.Credentials`

:returns:
    Headers as :class:`dict`.