input: Write a python function to get permutations of words in a sentence using itertools.
  assert get_permutations("the cat sat") == [('the', 'cat', 'sat'), ('the', 'sat', 'cat'), ('cat', 'the', 'sat'), ('cat', 'sat', 'the'), ('sat', 'the', 'cat'), ('sat', 'cat', 'the')]
  assert get_permutations("hello world") == [('hello', 'world'), ('world', 'hello')]
  assert get_permutations("a b c") == [('a', 'b', 'c'), ('a', 'c', 'b'), ('b', 'a', 'c'), ('b', 'c', 'a'), ('c', 'a', 'b'), ('c', 'b', 'a')]
output: def get_permutations(sentence):
      from itertools import permutations
      words = sentence.split()
      return list(permutations(words))