Check for Collection.intersect() bug that affects some Groovy versions

intersect-bug.groovy

// Check Groovy intersect bug
def checkIntersectBug() {
    def foo = [[1], [2], [3]]
    def bar = [[2], [3], [4]]
    if (foo.intersect(bar).size() != 2) {
        println '''Warning!

The version of Groovy that you are running contains a bug on Collection.intersect().
Upgrade to 2.4.7 or later.
See http://stackoverflow.com/questions/35493088/groovy-strange-collectionintersect-behaviour

This program will not function correctly under this version.
Exiting'''
        System.exit(1)
    }
}