def test_increment(): # type: () -> None
s = operation.Increment(1)
assert s.amount == 1
previous = operation.Increment(2)
new = s._merge(previous)
assert isinstance(new, operation.Increment)
assert new.amount == 3
def increment(self, attr, amount=1):
"""
在对象此字段上自增对应的数值，如果数值没有指定，默认为一。
:param attr: 字段名
:param amount: 自增量
:return: 当前对象
"""
return self.set(attr, operation.Increment(amount))
