1.12.2 How do i create a method that makes delayed tasks more simple

thats a noble try. you cant pass a method call as an argument, thats simply not how it works. change your object argument to a runnable, and pass the runnable instead, then when you use set, you can use

Code (Java):

set(() -> sender.sendMessage("test"), 10L);

/e

Code (Text):

() -> sender...

is a lambda construction of a runnable. this is the same as doing new Runnable() { run() { ... } }
then instead of creating a runnable in your set method, just use this runnable that youre passing as an argument

 

You need to make that method for a certain use, e.g. sending a message
replace object with a string and it will send a message later
As said above you can’t put call a method in an argument so you will have to do it this way or make a runnable each time

 

You cannot pass a void method as an argument.