How to use the @opencensus/core.TagMap function in @opencensus/core

tags.set(methodKey, { value: 'REPL' });
    tags.set(statusKey, { value: 'OK' });

    globalStats.record([{
      measure: mLineLengths,
      value: processedLine.length
    }], tags);

    globalStats.record([{
      measure: mLatencyMs,
      value: sinceInMilliseconds(endNanoseconds, startNanoseconds)
    }], tags);
  } catch (err) {
    console.log(err);

    const errTags = new TagMap();
    errTags.set(methodKey, { value: 'repl' });
    errTags.set(statusKey, { value: 'ERROR' });
    globalStats.record([{
      measure: mLatencyMs,
      value: sinceInMilliseconds(endNanoseconds, startNanoseconds)
    }], errTags);
  }

  // Restarts the start time for the REPL
  startNanoseconds = endNanoseconds;
});

tags.set(methodKey, { value: 'REPL' });
    tags.set(statusKey, { value: 'OK' });

    globalStats.record([{
      measure: mLineLengths,
      value: processedLine.length
    }], tags);

    globalStats.record([{
      measure: mLatencyMs,
      value: sinceInMilliseconds(endNanoseconds, startNanoseconds)
    }], tags);
  } catch (err) {
    console.log(err);

    const errTags = new TagMap();
    errTags.set(methodKey, { value: 'repl' });
    errTags.set(statusKey, { value: 'ERROR' });
    globalStats.record([{
      measure: mLatencyMs,
      value: sinceInMilliseconds(endNanoseconds, startNanoseconds)
    }], errTags);
  }

  // Restarts the start time for the REPL
  startNanoseconds = endNanoseconds;
});

lineReader.on('line', function (line) {
  // Read
  try {
    const processedLine = processLine(line); // Evaluate
    console.log(processedLine); // Print

    // Registers the end of our REPL
    [_, endNanoseconds] = process.hrtime();

    const tags = new TagMap();
    tags.set(methodKey, { value: 'REPL' });
    tags.set(statusKey, { value: 'OK' });

    globalStats.record([{
      measure: mLineLengths,
      value: processedLine.length
    }], tags);

    globalStats.record([{
      measure: mLatencyMs,
      value: sinceInMilliseconds(endNanoseconds, startNanoseconds)
    }], tags);
  } catch (err) {
    console.log(err);

    const errTags = new TagMap();

value: 1
    }], tags);

    tags.set(tagPhase, { value: valueTLSNegotiation });
    globalStats.record([{
      measure: mLatencyMs,
      value: 1
    }], tags);

    tags.set(tagPhase, { value: valueLoad });
    globalStats.record([{
      measure: mLatencyMs,
      value: 1
    }], tags);

    const tags1 = new TagMap();
    tags1.set(tagClient, { value: valueWeb });
    globalStats.record([{
      measure: mClickCount,
      value: 1
    }], tags1);
    res.status(200).send("Received").end();
    console.log('Competed recording metrics');
  } catch (err) {
    console.log(`Could not save stats: ${err}`);
    res.status(500).send("Error saving stats").end();
  }
  // [END web_client_monitoring_record]
});

lineReader.on('line', function (line) {
  // Read
  try {
    const processedLine = processLine(line); // Evaluate
    console.log(processedLine); // Print

    // Registers the end of our REPL
    [_, endNanoseconds] = process.hrtime();

    const tags = new TagMap();
    tags.set(methodKey, { value: 'REPL' });
    tags.set(statusKey, { value: 'OK' });

    globalStats.record([{
      measure: mLineLengths,
      value: processedLine.length
    }], tags);

    globalStats.record([{
      measure: mLatencyMs,
      value: sinceInMilliseconds(endNanoseconds, startNanoseconds)
    }], tags);
  } catch (err) {
    console.log(err);

    const errTags = new TagMap();

err.message
          );
        } else {
          span.setStatus(CanonicalCode.OK);
          span.addAttribute(
            GrpcPlugin.ATTRIBUTE_GRPC_STATUS_CODE,
            grpcTypes.status.OK.toString()
          );
        }
        span.addMessageEvent(MessageEventType.SENT, 1);

        // record stats: new RPCs on client-side inherit the tag context from
        // the current Context.
        const parentTagCtx = plugin.stats
          ? plugin.stats.getCurrentTagContext()
          : new TagMap();
        if (parentTagCtx.tags.size > 0) {
          GrpcPlugin.setTagContext(metadata, parentTagCtx);
        }
        parentTagCtx.set(
          clientStats.GRPC_CLIENT_METHOD,
          { value: span.name },
          UNLIMITED_PROPAGATION_MD
        );
        GrpcPlugin.recordStats(
          span.kind,
          parentTagCtx,
          originalArgs,
          res,
          Date.now() - startTime
        );

rootSpan.addAttribute(
          GrpcPlugin.ATTRIBUTE_GRPC_ERROR_MESSAGE,
          err.message
        );
      } else {
        rootSpan.setStatus(CanonicalCode.OK);
        rootSpan.addAttribute(
          GrpcPlugin.ATTRIBUTE_GRPC_STATUS_CODE,
          grpcTypes.status.OK.toString()
        );
      }
      rootSpan.addMessageEvent(MessageEventType.RECEIVED, 1);

      // record stats
      const parentTagCtx =
        GrpcPlugin.getTagContext(call.metadata) || new TagMap();
      parentTagCtx.set(
        serverStats.GRPC_SERVER_METHOD,
        { value: rootSpan.name },
        UNLIMITED_PROPAGATION_MD
      );
      const req = call.hasOwnProperty('request') ? call.request : {};
      GrpcPlugin.recordStats(
        rootSpan.kind,
        parentTagCtx,
        value,
        req,
        Date.now() - startTime
      );

      rootSpan.end();
      return callback(err, value, trailer, flags);

function main () {
  const tags1 = new TagMap();
  tags1.set(K1, V1);

  globalStats.withTagContext(tags1, () => {
    console.log('Enter Scope 1');
    printMap('Add Tags', tags1.tags);
    printMap('Current Tags == Default + tags1:',
    globalStats.getCurrentTagContext().tags);

    const tags2 = new TagMap();
    tags2.set(K2, V2);
    globalStats.withTagContext(tags2, () => {
      console.log('Enter Scope 2');
      printMap('Add Tags', tags2.tags);
      printMap('Current Tags == Default + tags1 + tags2:', globalStats.getCurrentTagContext().tags);

      const measurement = { measure: mLatencyMs, value: 10 };

globalStats.withTagContext(tags1, () => {
    console.log('Enter Scope 1');
    printMap('Add Tags', tags1.tags);
    printMap('Current Tags == Default + tags1:',
    globalStats.getCurrentTagContext().tags);

    const tags2 = new TagMap();
    tags2.set(K2, V2);
    globalStats.withTagContext(tags2, () => {
      console.log('Enter Scope 2');
      printMap('Add Tags', tags2.tags);
      printMap('Current Tags == Default + tags1 + tags2:', globalStats.getCurrentTagContext().tags);

      const measurement = { measure: mLatencyMs, value: 10 };
      globalStats.record([measurement]);
      console.log('Close Scope 2');
    });
    printMap('Current Tags == Default + tags1:', globalStats.getCurrentTagContext().tags);
    console.log('Close Scope 1');
  });
}