How to use the dialogflow.ContextsClient function in dialogflow

import * as dialogflow from "dialogflow";

const agentsClient = new dialogflow.AgentsClient();
const contextsClient = new dialogflow.ContextsClient();
const entityTypesClient = new dialogflow.EntityTypesClient();
const intentsClient = new dialogflow.IntentsClient();
const sessionEntityTypesClient = new dialogflow.SessionEntityTypesClient();
const sessionsClient = new dialogflow.SessionsClient();

// TODO: Add real significant tests

async function deleteContext(projectId, sessionId, contextId) {
  // [START dialogflow_delete_context]
  // Imports the Dialogflow library
  const dialogflow = require('dialogflow');

  // Instantiates clients
  const contextsClient = new dialogflow.ContextsClient();

  const contextPath = contextsClient.contextPath(
    projectId,
    sessionId,
    contextId
  );

  const request = {
    name: contextPath,
  };

  // Send the request for retrieving the context.
  const result = await contextsClient.deleteContext(request);
  console.log(`Context ${contextPath} deleted`);
  return result;
  // [END dialogflow_delete_context]

async function listContexts(projectId, sessionId) {
  // [START dialogflow_list_contexts]
  // Imports the Dialogflow library
  const dialogflow = require('dialogflow');

  // Instantiates clients
  const contextsClient = new dialogflow.ContextsClient();

  // The path to identify the agent that owns the contexts.
  const sessionPath = contextsClient.sessionPath(projectId, sessionId);

  const request = {
    parent: sessionPath,
  };

  // Send the request for listing contexts.
  const [response] = await contextsClient.listContexts(request);
  response.forEach(context => {
    console.log(`Context name: ${context.name}`);
    console.log(`Lifespan count: ${context.lifespanCount}`);
    console.log('Fields:');
    if (context.parameters !== null) {
      context.parameters.fields.forEach(field => {

.on('data', data => {
      if (data.recognitionResult) {
        console.log(
          `Intermediate transcript: ${data.recognitionResult.transcript}`
        );
      } else {
        console.log(`Detected intent:`);

        const result = data.queryResult;
        // Instantiates a context client
        const contextClient = new dialogflow.ContextsClient();

        console.log(`  Query: ${result.queryText}`);
        console.log(`  Response: ${result.fulfillmentText}`);
        if (result.intent) {
          console.log(`  Intent: ${result.intent.displayName}`);
        } else {
          console.log(`  No intent matched.`);
        }
        const parameters = JSON.stringify(struct.decode(result.parameters));
        console.log(`  Parameters: ${parameters}`);
        if (result.outputContexts && result.outputContexts.length) {
          console.log(`  Output contexts:`);
          result.outputContexts.forEach(context => {
            const contextId = contextClient.matchContextFromContextName(
              context.name
            );

audioConfig: {
        audioEncoding: encoding,
        sampleRateHertz: sampleRateHertz,
        languageCode: languageCode,
      },
    },
    inputAudio: inputAudio,
  };

  // Recognizes the speech in the audio and detects its intent.
  const [response] = await sessionClient.detectIntent(request);

  console.log('Detected intent:');
  const result = response.queryResult;
  // Instantiates a context client
  const contextClient = new dialogflow.ContextsClient();

  console.log(`  Query: ${result.queryText}`);
  console.log(`  Response: ${result.fulfillmentText}`);
  if (result.intent) {
    console.log(`  Intent: ${result.intent.displayName}`);
  } else {
    console.log(`  No intent matched.`);
  }
  const parameters = JSON.stringify(struct.decode(result.parameters));
  console.log(`  Parameters: ${parameters}`);
  if (result.outputContexts && result.outputContexts.length) {
    console.log(`  Output contexts:`);
    result.outputContexts.forEach(context => {
      const contextId = contextClient.matchContextFromContextName(context.name);
      const contextParameters = JSON.stringify(
        struct.decode(context.parameters)

const request = {
    session: sessionPath,
    queryInput: {
      event: {
        name: eventName,
        parameters: struct.encode({foo: 'bar'}),
        languageCode: languageCode,
      },
    },
  };

  const [response] = await sessionClient.detectIntent(request);
  console.log('Detected intent');
  const result = response.queryResult;
  // Instantiates a context client
  const contextClient = new dialogflow.ContextsClient();

  console.log(`  Query: ${result.queryText}`);
  console.log(`  Response: ${result.fulfillmentText}`);
  if (result.intent) {
    console.log(`  Intent: ${result.intent.displayName}`);
  } else {
    console.log(`  No intent matched.`);
  }
  const parameters = JSON.stringify(struct.decode(result.parameters));
  console.log(`  Parameters: ${parameters}`);
  if (result.outputContexts && result.outputContexts.length) {
    console.log(`  Output contexts:`);
    result.outputContexts.forEach(context => {
      const contextId = contextClient.matchContextFromContextName(context.name);
      const contextParameters = JSON.stringify(
        struct.decode(context.parameters)

async function createContext(projectId, sessionId, contextId, lifespanCount) {
  // [START dialogflow_create_context]
  // Imports the Dialogflow library
  const dialogflow = require('dialogflow');

  // Instantiates clients
  const contextsClient = new dialogflow.ContextsClient();

  const sessionPath = contextsClient.sessionPath(projectId, sessionId);
  const contextPath = contextsClient.contextPath(
    projectId,
    sessionId,
    contextId
  );

  const createContextRequest = {
    parent: sessionPath,
    context: {
      name: contextPath,
      lifespanCount: lifespanCount,
    },
  };