method Deno.UnsafeCallback.prototype.close
UnsafeCallback.prototype.close(): void
Removes the C function pointer associated with this instance.
Continuing to use the instance or the C function pointer after closing
the `UnsafeCallback` will lead to errors and crashes.
Calling this method sets the callback's reference counting to zero,
stops the callback from waking up the Deno event loop when called from
foreign threads and no longer keeps Deno's process from exiting.
void