'Check if an extension supported by a plugin has been loaded.'

def check_if_plugin_extensions_loaded(self):

    plugin_extensions = self.get_supported_extension_aliases()
    missing_aliases = (plugin_extensions - set(self.extensions))
    missing_aliases -= _PLUGIN_AGNOSTIC_EXTENSIONS
    if missing_aliases:
        raise exceptions.ExtensionsNotFound(extensions=list(missing_aliases))
