assertNull()function

assertNull(value: Nullable<T>, caller: AnyCaller = assertNull): asserts value is T

Param	Type
`value`	`Nullable<T>`	The value to assert. required
`caller`	`AnyCaller`	Function used to attribute a thrown error to the calling site. Defaults to `assertNull`

Return
`asserts value is T`	Nothing; narrows `value` to `T`.

Throws
`unknown`	`RequiredError` if `value` is not `null`.

Assert that a value is null.