Pattern: Use of collect.flatten()
Issue: -
In many cases collectMany() yields the same result as collect.flatten(). It is easier to understand and more clearly conveys the intent.
Example of violations:
def l = [1, 2, 3, 4]
l.collect{ [it, it*2] }.flatten() // suboptimal
l.collectMany{ [it, it*2] } // same functionality, better readability