def runListReferenceBases(self, id_, requestArgs):
        compoundId = datamodel.ReferenceCompoundId.parse(id_)
        referenceSet = self.getDataRepository().getReferenceSet(
            compoundId.referenceSetId)
        reference = referenceSet.getReference(id_)
        start = _parseIntegerArgument(requestArgs, 'start', 0)
        end = _parseIntegerArgument(requestArgs, 'end', reference.getLength())
        if 'pageToken' in requestArgs:
            pageTokenStr = requestArgs['pageToken']
            start = _parsePageToken(pageTokenStr, 1)[0]

        chunkSize = self._maxResponseLength
        nextPageToken = None
        if start + chunkSize < end:
            end = start + chunkSize
            nextPageToken = str(start + chunkSize)
        sequence = reference.getBases(start, end)

        # build response
        response = protocol.ListReferenceBasesResponse()
        response.offset = start
        response.sequence = sequence
        response.nextPageToken = nextPageToken
        return response.toJsonString()

    # Get requests.
Runs a listReferenceBases request for the specified ID and
dataset/ETHPy150Open ga4gh/server/ga4gh/backend.py/Backend.runListReferenceBases