input: Write a function to return an array with the running total of numbers in a given list using numpy. If the list is empty, return an empty list.
  assert np.array_equal(runningTotal([]), []) == True
  assert np.array_equal(runningTotal([1, 2, 3, 4]), [1, 3, 6, 10]) == True
  assert np.array_equal(runningTotal([10, -2, 5, 3]), [10, 8, 13, 16]) == True
  assert np.array_equal(runningTotal([0, 0, 0, 0]), [0, 0, 0, 0]) == True
  assert np.array_equal(runningTotal([-1, -1, -1, -1]), [-1, -2, -3, -4]) == True
output: import numpy as np
  
  def runningTotal(lst):
      if not lst:
          return []
      return np.cumsum(lst).tolist()