groovy:000> def x(a,b,c){[a..b].each{println it*c}}
===> true

groovy:000> x(1, 10, 2)
[1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 1, 2, 3, 4, 5, 6, 7, 8, 9, 10]
===> [1..10]