input: from typing import List
  
  
  def sum_array(array: List[int]) -> int:
      """
      A function that takes in an array of numbers and returns the sum of all the numbers.
      >>> sum_array([1, 2, 3])
      6
      >>> sum_array([-1, 0, 1])
      0
      >>> sum_array([])
      0
      """
      return sum(array)
output:     return sum(array)