---
title: UnderlyingSourceCancelCallback
url: https://www.fastly.com/documentation/reference/compute/sdks/javascript/js-compute/globals/interface.UnderlyingSourceCancelCallback/
---

**Kind:** Interface  
**Module:** [globals](https://www.fastly.com/documentation/reference/compute/sdks/javascript/js-compute/globals/)  
**Package:** @fastly/js-compute 4.0.1  
**Source:** https://github.com/fastly/js-compute-runtime/blob/70cf30af4e657879b2d1e7eafab880e39e3a3f7d/types/globals.d.ts#L1715

## Methods

### __call

**Source:** https://github.com/fastly/js-compute-runtime/blob/70cf30af4e657879b2d1e7eafab880e39e3a3f7d/types/globals.d.ts#L1716

```javascript
__call(reason?: any): void | PromiseLike<void>
```

**Parameters**

- `reason`: `any` (optional)

**Returns**

`void | PromiseLike<void>`