def METHOD_NAME(self, request):
    """Given a tag and single run, return array of ScalarEvents."""
    tag = request.args.get("tag")
    run = request.args.get("run")
    if tag is None or run is None:
        raise errors.InvalidArgumentError(
            "Both run and tag must be specified: tag=%r, run=%r"
            % (tag, run)
        )
    ctx = plugin_util.context(request.environ)
    experiment = plugin_util.experiment_id(request.environ)
    output_format = request.args.get("format")
    (body, mime_type) = self.scalars_impl(
        ctx, tag, run, experiment, output_format
    )
    return http_util.Respond(request, body, mime_type)