Function tap

tap<T>(value: T, callback: (value: T) => void): T
Pass the value through the callback, and return the value
Type Parameters
- T
Parameters
- value: T
- callback: (value: T) => void
Returns T
Example
```
function createUser(name: string): User {
  return tap(new User, user => {
    user.name = name
  })
}
```
- Defined in function.ts:114