我有一个类似的清单：
def given = [
[Country:'Japan',Flag:'Yes',Event:'New Year', Amount:70],
[Country:'china',Flag:'No',Event:'Spring Festival', Amount:60],
[Country:'us',Flag:'Yes',Event:'Labour Day', Amount:10],
[Country:'us',Flag:'Yes',Event:'Labour Day', Amount:20]
]
我期望会是这样的：
[
[Country:'Japan',Flag:'Yes',Event:'New Year', Amount:70],
[Country:'china',Flag:'No',Event:'Spring Festival', Amount:60],
[Country:'us',Flag:'Yes',Event:'Labour Day', Amount:30]
]