can't use row_swap_images()

[omarcostahamido]

I'm getting this error:

Traceback (most recent call last):
  File "<ipython-input-14-654be539333f>", line 1, in <module>
    new_ac, new_cc = qb.row_swap_images(ac,cc,0.333)
  File "/opt/conda/lib/python3.8/site-packages/quantumblur/quantumblur.py", line 832, in row_swap_images
    rows[0][y], rows[1][y] = swap_images(rows[0][y], rows[1][y], fraction, log=log)
  File "/opt/conda/lib/python3.8/site-packages/quantumblur/quantumblur.py", line 687, in swap_images
    nh0, nh1 = swap_heights(heights0[j], heights1[j], fraction, log=log)
  File "/opt/conda/lib/python3.8/site-packages/quantumblur/quantumblur.py", line 587, in swap_heights
    circuits = [height2circuit(height) for height in [height0,height1]]
  File "/opt/conda/lib/python3.8/site-packages/quantumblur/quantumblur.py", line 587, in <listcomp>
    circuits = [height2circuit(height) for height in [height0,height1]]
  File "/opt/conda/lib/python3.8/site-packages/quantumblur/quantumblur.py", line 382, in height2circuit
    state = normalize(state)
  File "/opt/conda/lib/python3.8/site-packages/quantumblur/quantumblur.py", line 303, in normalize
    ket[j] = float(amp)/math.sqrt(N)
ZeroDivisionError: float division by zero