### Install vk-call Library

Source: https://github.com/vkcom/node-vk-call/blob/master/README.md

Installs the vk-call library using the npm package manager.

```Shell
npm install vk-call
```

--------------------------------

### Start VK Group Long Poll API

Source: https://github.com/vkcom/node-vk-call/blob/master/README.md

Shows how to initialize the VK object for group Long Poll API by providing a groupId and start listening for events using `persistentLongpoll`, processing incoming messages.

```JavaScript
const VK = require('vk-call').VK;
const vk = new VK({
  token: "YOUR TOKEN HERE",
  version: "5.124",
  timeout: 10000,
  groupId: 1,
});

const longpoll = vk.persistentLongpoll();
longpoll.sink.on("data", (events) => {
  events.forEach((event) => {
    const message = event.object.message;
    if (/^hello/i.test(msg.text)) {
      vk.call('messages.send', {
        user_id: message.from_id,
        message: "Hi!",
        random_id: 0,
      }).catch((error) => console.error(error));
    }
  })
});
```

--------------------------------

### Import VK Object

Source: https://github.com/vkcom/node-vk-call/blob/master/README.md

Imports the main VK class from the vk-call library to start interacting with the VK API.

```JavaScript
const VK = require('vk-call').VK;
```

--------------------------------

### Make Single API Call with vk-call

Source: https://github.com/vkcom/node-vk-call/blob/master/README.md

Demonstrates initializing the VK object with configuration (token, version, timeout) and making a single API call using the `call` method, handling the promise result.

```JavaScript
const VK = require('vk-call').VK;
const vk = new VK({
  token: "YOUR TOKEN HERE",
  version: "5.124",
  timeout: 10000
});

api.call("users.get", { user_ids: 1 })
  .then(users => console.log(users));
```

--------------------------------

### Run Library Tests

Source: https://github.com/vkcom/node-vk-call/blob/master/README.md

Commands to execute the library's test suite using npm, including a watch mode for development.

```Shell
npm test
```

```Shell
npm test-watch
```

--------------------------------

### Chain VK API Calls with vk-call

Source: https://github.com/vkcom/node-vk-call/blob/master/README.md

Illustrates initializing and using the `Chain` object obtained via `vk.chain()` to append multiple API calls (`append`) and execute them in a batch using `done`, processing the array of results.

```JavaScript
const VK = require('vk-call').VK;
const vk = new vk({
  token: "YOUR TOKEN",
  version: "5.124"
});

var chain = vk.chain();

chain.append("users.get", { user_ids: 1 })
  .then((users) => console.log(users));
  
chain.append("groups.getById", { group_ids: 1 })
  .then(groups => console.log(groups));
  
chain.done()
  .then((result) => {
    var users = result[0];
    var groups = result[1];
    console.log(users, groups);
  });
  
chain.append("users.get", { user_ids: 2 });

// Throws error, because chain ended after done
```

--------------------------------

### Access VK API Error Constants

Source: https://github.com/vkcom/node-vk-call/blob/master/README.md

Shows how to access predefined constants representing common VK API error codes from the errors module for easier error handling and comparison.

```JavaScript
var errors = require('vk-call').errors;
assert(errors.NOT_DOMAIN_ERROR === -1);
assert(errors.UKNOWN_ERROR === 1);
assert(errors.UNKNOWN_METHOD === 3);
```

--------------------------------

### Access VKError Name Constants

Source: https://github.com/vkcom/node-vk-call/blob/master/README.md

Shows how to access constants (`NOT_DOMAIN_NAME`, `DOMAIN_NAME`) from the errors module to distinguish between domain (API) errors and other types of failures.

```JavaScript
var errors = require('vk-call').errors;
errors.NOT_DOMAIN_NAME
errors.DOMAIN_NAME
```

--------------------------------

### Import VKError Class

Source: https://github.com/vkcom/node-vk-call/blob/master/README.md

Imports the VKError class from the errors module, which is used to wrap all errors returned by the vk-call library.

```JavaScript
var VKError = require('vk-call').errors.VKError;
```

=== COMPLETE CONTENT === This response contains all available snippets from this library. No additional content exists. Do not make further requests.