Write a function to find all possible combinations of the elements of a given list.
def combinations_list(list1):
    if len(list1) == 0:
        return [[]]
    result = []
    for el in combinations_list(list1[1:]):
        result += [el, el+[list1[0]]]
    return result
<s>[INST]<<SYS>>Given a task and its code, generate test cases for the code.<</SYS>>Write a function to find all possible combinations of the elements of a given list.
def combinations_list(list1):
    if len(list1) == 0:
        return [[]]
    result = []
    for el in combinations_list(list1[1:]):
        result += [el, el+[list1[0]]]
    return result[/INST]assert combinations_list(['orange', 'red', 'green', 'blue'])==[[], ['orange'], ['red'], ['red', 'orange'], ['green'], ['green', 'orange'], ['green', 'red'], ['green', 'red', 'orange'], ['blue'], ['blue', 'orange'], ['blue', 'red'], ['blue', 'red', 'orange'], ['blue', 'green'], ['blue', 'green', 'orange'], ['blue', 'green', 'red'], ['blue', 'green', 'red', 'orange']]
assert combinations_list(['red', 'green', 'blue', 'white', 'black', 'orange'])==[[], ['red'], ['green'], ['green', 'red'], ['blue'], ['blue', 'red'], ['blue', 'green'], ['blue', 'green', 'red'], ['white'], ['white', 'red'], ['white', 'green'], ['white', 'green', 'red'], ['white', 'blue'], ['white', 'blue', 'red'], ['white', 'blue', 'green'], ['white', 'blue', 'green', 'red'], ['black'], ['black', 'red'], ['black', 'green'], ['black', 'green', 'red'], ['black', 'blue'], ['black', 'blue', 'red'], ['black', 'blue', 'green'], ['black', 'blue', 'green', 'red'], ['black', 'white'], ['black', 'white', 'red'], ['black', 'white', 'green'], ['black', 'white', 'green', 'red'], ['black', 'white', 'blue'], ['black', 'white', 'blue', 'red'], ['black', 'white', 'blue', 'green'], ['black', 'white', 'blue', 'green', 'red'], ['orange'], ['orange', 'red'], ['orange', 'green'], ['orange', 'green', 'red'], ['orange', 'blue'], ['orange', 'blue', 'red'], ['orange', 'blue', 'green'], ['orange', 'blue', 'green', 'red'], ['orange', 'white'], ['orange', 'white', 'red'], ['orange', 'white', 'green'], ['orange', 'white', 'green', 'red'], ['orange', 'white', 'blue'], ['orange', 'white', 'blue', 'red'], ['orange', 'white', 'blue', 'green'], ['orange', 'white', 'blue', 'green', 'red'], ['orange', 'black'], ['orange', 'black', 'red'], ['orange', 'black', 'green'], ['orange', 'black', 'green', 'red'], ['orange', 'black', 'blue'], ['orange', 'black', 'blue', 'red'], ['orange', 'black', 'blue', 'green'], ['orange', 'black', 'blue', 'green', 'red'], ['orange', 'black', 'white'], ['orange', 'black', 'white', 'red'], ['orange', 'black', 'white', 'green'], ['orange', 'black', 'white', 'green', 'red'], ['orange', 'black', 'white', 'blue'], ['orange', 'black', 'white', 'blue', 'red'], ['orange', 'black', 'white', 'blue', 'green'], ['orange', 'black', 'white', 'blue', 'green', 'red']]
assert combinations_list(['red', 'green', 'black', 'orange'])==[[], ['red'], ['green'], ['green', 'red'], ['black'], ['black', 'red'], ['black', 'green'], ['black', 'green', 'red'], ['orange'], ['orange', 'red'], ['orange', 'green'], ['orange', 'green', 'red'], ['orange', 'black'], ['orange', 'black', 'red'], ['orange', 'black', 'green'], ['orange', 'black', 'green', 'red']]</s>