input: Write a python function to find the largest number in a list.
  assert get_largest_number([2, 11, 15, 9, 5]) == 15
  assert get_largest_number([1, 2, 3, 4, 5]) == 5
  assert get_largest_number([5, 5, 5, 5, 5]) == 5
output: def get_largest_number(numbers):
      return max(numbers)