How to use the grlc.gquery.get_metadata function in grlc

def test_get_metadata(self):
        rq, _ = self.loader.getTextForName('test-sparql')

        metadata = gquery.get_metadata(rq, '')
        self.assertIn('type', metadata, 'Should have a type field')
        self.assertIn('variables', metadata, 'Should have a variables field')
        self.assertEqual(metadata['type'], 'SelectQuery',
                         'Should be type SelectQuery')
        self.assertIsInstance(
            metadata['variables'], list, 'Should be a list of variables')
        for var in metadata['variables']:
            self.assertIsInstance(var, rdflib.term.Variable,
                                  'Should be of type Variable')

def process_sparql_query_text(query_text, loader, call_name, extraMetadata):
    # We get the endpoint name first, since some query metadata fields (eg enums) require it

    endpoint, auth = gquery.guess_endpoint_uri(query_text, loader)
    glogger.debug("Read query endpoint: {}".format(endpoint))

    try:
        query_metadata = gquery.get_metadata(query_text, endpoint)
    except Exception:
        raw_repo_uri = loader.getRawRepoUri()
        raw_query_uri = raw_repo_uri + ' / ' + call_name
        glogger.error("Could not parse query at {}".format(raw_query_uri))
        glogger.error(traceback.print_exc())
        return None

    tags = query_metadata['tags'] if 'tags' in query_metadata else []

    summary = query_metadata['summary'] if 'summary' in query_metadata else ""

    description = query_metadata['description'] if 'description' in query_metadata else ""

    method = query_metadata['method'].lower() if 'method' in query_metadata else ""
    if method not in ['get', 'post', 'head', 'put', 'delete', 'options', 'connect']:
        method = ""

rewritten_query = gquery.rewrite_query(query_metadata['original_query'], query_metadata['parameters'], requestArgs)

    # Rewrite query using pagination
    if query_metadata['type'] == 'SelectQuery' and 'pagination' in query_metadata:
        rewritten_query = gquery.paginate_query(rewritten_query, query_metadata['pagination'], requestArgs)

    resp = None
    headers = {}

    # If we have a mime field, we load the remote dump and query it locally
    if 'mime' in query_metadata and query_metadata['mime']:
        glogger.debug(
            "Detected {} MIME type, proceeding with locally loading remote dump".format(query_metadata['mime']))
        g = Graph()
        try:
            query_metadata = gquery.get_metadata(raw_sparql_query, endpoint)
            g.parse(endpoint, format=query_metadata['mime'])
            glogger.debug("Local RDF graph loaded successfully with {} triples".format(len(g)))
        except Exception as e:
            glogger.error(e)
        results = g.query(rewritten_query, result='sparql')
        # Prepare return format as requested
        resp_string = ""
        if 'application/json' in acceptHeader or (content and 'application/json' in static.mimetypes[content]):
            resp_string = results.serialize(format='json')
            glogger.debug("Results of SPARQL query against locally loaded dump: {}".format(resp_string))
        elif 'text/csv' in acceptHeader or (content and 'text/csv' in static.mimetypes[content]):
            resp_string = results.serialize(format='csv')
            glogger.debug("Results of SPARQL query against locally loaded dump: {}".format(resp_string))
        else:
            return 'Unacceptable requested format', 415, {}
        glogger.debug("Finished processing query against RDF dump, end of use case")

def dispatchSPARQLQuery(raw_sparql_query, loader, requestArgs, acceptHeader, content, formData, requestUrl):
    endpoint, auth = gquery.guess_endpoint_uri(raw_sparql_query, loader)
    if endpoint == '':
        return 'No SPARQL endpoint indicated', 407, {}

    glogger.debug("=====================================================")
    glogger.debug("Sending query to SPARQL endpoint: {}".format(endpoint))
    glogger.debug("=====================================================")

    query_metadata = gquery.get_metadata(raw_sparql_query, endpoint)

    acceptHeader = 'application/json' if isinstance(raw_sparql_query, dict) else acceptHeader
    pagination = query_metadata['pagination'] if 'pagination' in query_metadata else ""

    rewritten_query = query_metadata['query']

    # Rewrite query using parameter values
    if query_metadata['type'] == 'SelectQuery' or query_metadata['type'] == 'ConstructQuery':
        rewritten_query = gquery.rewrite_query(query_metadata['original_query'], query_metadata['parameters'], requestArgs)

    # Rewrite query using pagination
    if query_metadata['type'] == 'SelectQuery' and 'pagination' in query_metadata:
        rewritten_query = gquery.paginate_query(rewritten_query, query_metadata['pagination'], requestArgs)

    resp = None
    headers = {}