input: Write a function to calculate the running total of numbers in a given list using numpy. Return an array where each element is the cumulative sum of the elements up to that position in the input list. If the input list is empty, return an empty list.
  assert np.array_equal(runningTotal([1, 2, 3, 4, 5]), np.array([1, 3, 6, 10, 15]))==True
  assert np.array_equal(runningTotal([1, 1, 1, 1]), np.array([1, 2, 3, 4]))==True
  assert np.array_equal(runningTotal([5, 4, 3, 2, 1]), np.array([5, 9, 12, 14, 15]))==True
  assert np.array_equal(runningTotal([]), np.array([]))==True
output: import numpy as np
  
  def runningTotal(lst):
      if not lst:
          return np.array([])
      return np.cumsum(lst)