input: def runningTotal(arr):
      """Given a list of numbers, return an array with the running total of numbers in the list.
      >>> runningTotal([1, 2, 3, 4, 5])
      array([1, 3, 6, 10, 15])
      >>> runningTotal([10, 20, 30])
      array([10, 30, 60])
      """
      import numpy as np
      return np.cumsum(arr)
output:     import numpy as np
      return np.cumsum(arr)