Groovy 1.7.4 adds the minus() method to the Map class. The result is a new map with the entries of the map minus the same entries from the second map.
def m1 = [user: 'mrhaki', age: 37] def m2 = [user: 'mrhaki', name: 'Hubert'] def m3 = [user: 'Hubert', age: 37] assert [age: 37] == m1 - m2 assert [user: 'mrhaki'] == m1 - m3
