docs: def updateArray(self, array, indices, value):
          """
          updates array so that pixels at indices take on value
          :param array: (m,n) array to adjust
          :param indices: flattened image indices to change value
          :param value: new value to assign
          :return: the changed (m,n) array
          """
          lin = np.arange(array.size)
          new_array = array.flatten()
          new_array[lin[indices]] = value
          return new_array.reshape(array.shape)