curl -X POST https://api.box.com/2.0/webhooks \
     -H 'Authorization: Bearer <ACCESS_TOKEN>'
     -H 'Content-Type: application/json" '
     -d '{
       "target": {
         "id": "21322", 
         "type": "file"
       }, 
       "address": "https://example.com/webhooks",
       "triggers": [
         "FILE.PREVIEWED"
       ]
     }'

var webhookParams = new BoxWebhookRequest()
{
    Target = new BoxRequestEntity()
    {
        Type = BoxType.file,
        Id = "22222"
    },
    Triggers = new List<string>()
    {
        "FILE.PREVIEWED"
    },
    Address = "https://example.com/webhook"
};
BoxWebhook webhook = await client.WebhooksManager.CreateWebhookAsync(webhookParams);

// Listen for preview events for a file
BoxFile file = new BoxFile(api, id);
BoxWebHook.Info webhookInfo = BoxWebHook.create(file, url, BoxWebHook.Trigger.FILE.PREVIEWED);

file = client.file(file_id='12345')
webhook = client.create_webhook(file, ['FILE.PREVIEWED'], 'https://example.com')
print('Webhook ID is {0} and the address is {1}'.format(webhook.id, webhook.address))

// Attach a webhook that sends a notification to https://example.com/webhook when
//   file 11111 is renamed or downloaded.
client.webhooks.create(
	'11111',
	client.itemTypes.FILE,
	'https://example.com/webhook',
	[
		client.webhooks.triggerTypes.FILE.RENAMED,
		client.webhooks.triggerTypes.FILE.DOWNLOADED
	])
	.then(webhook => {
		/* webhook -> {
			id: '12345',
			type: 'webhook',
			target: { id: '11111', type: 'file' },
			created_by: 
			{ type: 'user',
				id: '33333',
				name: 'Example User',
				login: 'user@example.com' },
			created_at: '2016-05-09T17:41:27-07:00',
			address: 'https://example.com/webhook',
			triggers: [ 'FILE.RENAMED', 'FILE.UPLOADED' ] }
		*/
	});

client.webhooks.create(targetType: "file", targetId: "1234", triggers: [.fileDownloaded], address: "www.testurl.com") { (result: Result<Webhook, BoxSDKError>) in
    guard case let .success(webhook) = result else {
        print("Error creating webhook")
        return
    }

    print("Created webhook \"\(webhook.id)\"")
}