input: Write a function to compute the running total of numbers in a given list using numpy. The function should return an array where each element at index `i` is the cumulative sum of elements up to index `i` in the input list. If the input list is empty, the function should return an empty list.
  
  import numpy as np
  
  def runningTotal(arr):
      return np.cumsum(arr)
  
  assert np.array_equal(runningTotal([1, 2, 3, 4]), [1, 3, 6, 10])==True
  assert np.array_equal(runningTotal([5, -1, 3, 0]), [5, 4, 7, 7])==True
  assert np.array_equal(runningTotal([]), [])==True
  assert np.array_equal(runningTotal([10]), [10])==True
  assert np.array_equal(runningTotal([-1, -2, -3, -4]), [-1, -3, -6, -10])==True
output: import numpy as np
  
  def runningTotal(arr):
      return np.cumsum(arr)