upcomingInput method
Implementation
String upcomingInput() {
var next = match;
if (next.length < 20) {
next += input.substring(0, math.min(20 - next.length, input.length));
}
return (next.substring(0, math.min(20, next.length)) + (next.length > 20 ? '...' : '')).replaceAll('\n', '');
}