A single-argument scheduling function (such as requestAnimationFrame,
setImmediate, or queueMicrotask). The rule scheduler will call it from time
to time with a single callback. The scheduling function should then arrange
for that callback to be invoked once at some future point, when it is the
desired time for all pending rules on that scheduler to run.
A single-argument scheduling function (such as requestAnimationFrame, setImmediate, or queueMicrotask). The rule scheduler will call it from time to time with a single callback. The scheduling function should then arrange for that callback to be invoked once at some future point, when it is the desired time for all pending rules on that scheduler to run.