Runs :meth:`arca.DockerBackend.validate_configuration` and checks extra:

        * ``box`` format
        * ``provider`` format
        * ``use_registry_name`` is set and ``registry_pull_only`` is not enabled.

def validate_configuration(self):
        """ Runs :meth:`arca.DockerBackend.validate_configuration` and checks extra:

        * ``box`` format
        * ``provider`` format
        * ``use_registry_name`` is set and ``registry_pull_only`` is not enabled.
        """
        super().validate_configuration()

        if self.use_registry_name is None:
            raise ArcaMisconfigured("Use registry name setting is required for VagrantBackend")

        if not re.match(r"^[a-z]+/[a-zA-Z0-9\-_]+$", self.box):
            raise ArcaMisconfigured("Provided Vagrant box is not valid")

        if not re.match(r"^[a-z_]+$", self.provider):
            raise ArcaMisconfigured("Provided Vagrant provider is not valid")

        if self.registry_pull_only:
            raise ArcaMisconfigured("Push must be enabled for VagrantBackend")