The return statement stops the execution of a function or code block and returns a value from that function or code block.
function myFunction ( ) {
return Math.PI;
}
If your kBridge code is a single statement with no code block, you don't need to use the return statement.
this.height
But if your Rule is more complex, you will need the return statement:
If ( this.load < 200)
{ return 3 } else
{ return 8 }