I need help with simulating stopped time i need a string of code that does this if anybody can help that would be great.

Im working on a mod that can stop time for version 1.14.4 and everytthing is pretty much done i just need a string of custom code that "stops time", which i dont know how to do because i only took like one semester of computer programming, can anybody provide said code for me? if so this would help out BIG time, once im done ill make sure everything is good and release it to the public. 

i tried this below

try{Thread.sleep(10000);}catch(InterruptedException ex){Thread.currentThread().interrupt();}

but its a bit how do i put this, not that good?