def get_credential(self, credential_type):
if self.has_credential():<EOL><INDENT>return self._credential<EOL><DEDENT>else:<EOL><INDENT>raise IllegalState()<EOL><DEDENT>
Gets the credential represented by the given ``Type`` for transport to a remote service.

        :param credential_type: the credential format ``Type``
        :type credential_type: ``osid.type.Type``
        :return: the credential
        :rtype: ``object``
        :raise: ``IllegalState`` -- ``has_credential()`` is ``false``
        :raise: ``NullArgument`` -- ``credential_type`` is ``null``
        :raise: ``Unsupported`` -- the given ``credential_type`` is not supported

        *compliance: mandatory -- This method must be implemented.*
        *implementation notes*: A provider may support multiple
        credential formats for a variety of applications.