Why my assertion is failing
As on the image you can see Mylist and CityList are same.
But at the assertion get failed.
Forum Discussion
try to compare single item at once, hope you will find the error that way.
Use in only to compare single items from a list. Use equals to compare the whole list, or assert that each item from the first list is in the second list.
def a = [1,2]
def b = [1,2,3]
def c = [[1,2],3]
def d = [1,2]
assert (a in c)
assert !(a in b)
a.each { assert it in b }
assert a == d