   E       AssertionError: 
   E       Arrays are not equal
   E       
   E       nan location mismatch:
   E        ACTUAL: array([[ 0.,  1.],
   E              [nan, nan],
   E              [ 2.,  1.],
   E              [nan, nan]])
   E        DESIRED: array([[nan, nan],
   E              [ 0.,  1.],
   E              [ 2.,  1.],
   E              [nan, nan]])
