Merge multiple callback functions into a single function that calls all of them in sequence.
import mergeCallbacks from 'merge-callbacks'
const callback1 = (x: number) => console.log('First:', x)
const callback2 = (x: number) => console.log('Second:', x)
const combined = mergeCallbacks([callback1, callback2])
combined(42); // Logs "First: 42" followed by "Second: 42"