How to use the @opencensus/core.MessageEventType.SENT function in @opencensus/core

if (options.host || options.hostname) {
            const value = options.host || options.hostname
            span.addAttribute(HttpPlugin.ATTRIBUTE_HTTP_HOST, `${value}`)
          }
          span.addAttribute(HttpPlugin.ATTRIBUTE_HTTP_METHOD, method)
          span.addAttribute(HttpPlugin.ATTRIBUTE_HTTP_PATH, `${options.path}`)
          span.addAttribute(HttpPlugin.ATTRIBUTE_HTTP_ROUTE, `${options.path}`)
          if (userAgent) {
            span.addAttribute(
                HttpPlugin.ATTRIBUTE_HTTP_USER_AGENT, userAgent.toString())
          }
          span.addAttribute(HttpPlugin.ATTRIBUTE_HTTP_STATUS_CODE, `${response.statusCode}`)
          span.setStatus(HttpPlugin.convertTraceStatus(response.statusCode || 0))

          // Message Event ID is not defined
          span.addMessageEvent(MessageEventType.SENT, uuid.v4().split('-').join(''))

          span.end()
        })

err.code.toString()
            );
          }
          span.addAttribute(GrpcPlugin.ATTRIBUTE_GRPC_ERROR_NAME, err.name);
          span.addAttribute(
            GrpcPlugin.ATTRIBUTE_GRPC_ERROR_MESSAGE,
            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,

const userAgent =
            headers['user-agent'] || headers['User-Agent'] || null

        span.addAttribute(Http2Plugin.ATTRIBUTE_HTTP_HOST, `${url.parse(authority).host}`)
        span.addAttribute(
            Http2Plugin.ATTRIBUTE_HTTP_METHOD, `${headers[':method']}`)
        span.addAttribute(
            Http2Plugin.ATTRIBUTE_HTTP_PATH, `${headers[':path']}`)
        span.addAttribute(
            Http2Plugin.ATTRIBUTE_HTTP_ROUTE, `${headers[':path']}`)
        if (userAgent) {
          span.addAttribute(
              Http2Plugin.ATTRIBUTE_HTTP_USER_AGENT, `${userAgent}`)
        }

        span.addMessageEvent(MessageEventType.SENT, uuid.v4().split('-').join(''))

        span.end()
      })

);
        span.addAttribute(
          Http2Plugin.ATTRIBUTE_HTTP_PATH,
          `${headers[':path']}`
        );
        span.addAttribute(
          Http2Plugin.ATTRIBUTE_HTTP_ROUTE,
          `${headers[':path']}`
        );
        if (userAgent) {
          span.addAttribute(
            Http2Plugin.ATTRIBUTE_HTTP_USER_AGENT,
            `${userAgent}`
          );
        }
        span.addMessageEvent(MessageEventType.SENT, 1);
        span.end();
      });

const adaptMessageEventType = (
  type: MessageEventType
): opencensus.proto.trace.v1.Span.TimeEvent.MessageEvent.Type => {
  switch (type) {
    case MessageEventType.SENT: {
      return opencensus.proto.trace.v1.Span.TimeEvent.MessageEvent.Type.SENT;
    }
    case MessageEventType.RECEIVED: {
      return opencensus.proto.trace.v1.Span.TimeEvent.MessageEvent.Type
        .RECEIVED;
    }
    default: {
      return opencensus.proto.trace.v1.Span.TimeEvent.MessageEvent.Type
        .TYPE_UNSPECIFIED;
    }
  }
};

span.addAttribute(
              HttpPlugin.ATTRIBUTE_HTTP_USER_AGENT,
              userAgent.toString()
            );
          }
          if (response.statusCode) {
            span.addAttribute(
              HttpPlugin.ATTRIBUTE_HTTP_STATUS_CODE,
              response.statusCode.toString()
            );
            span.setStatus(HttpPlugin.parseResponseStatus(response.statusCode));
            tags.set(stats.HTTP_CLIENT_STATUS, {
              value: response.statusCode.toString(),
            });
          }
          span.addMessageEvent(MessageEventType.SENT, 1);

          if (plugin.options.applyCustomAttributesOnSpan) {
            plugin.options.applyCustomAttributesOnSpan(span, request, response);
          }

          HttpPlugin.recordStats(span.kind, tags, Date.now() - startTime);
          span.end();
        });