Macro track_instant 

macro_rules! track_instant {
    ($category:expr, $track:expr, $name:expr $(, $key:expr => $val:expr)* $(,)?) => { ... };
}

Writes an instant event to a custom track.

NOTE: This macro requires API level 31 or higher because the underlying virtual thread (VThread) support was stabilized and introduced in Fuchsia API level 31.