Convenience defer technique for passing execution to a thread pool in Groovy

threadpool.groovy

import java.util.concurrent.Callable
import java.util.concurrent.Executors

def THREADS = 2
def pool = Executors.newFixedThreadPool(THREADS)
def done = 0
	
def defer = { closure -> 
	pool.submit( closure as Callable )
}

for ( def i = 0; i < 10; i++ ) {
	def j = i+1
	defer {
		Thread.sleep(1000)
		println "Executing task ${j}"
	}
}

It may require adding at the end:

pool?.shutdown()