old_contents: def transform(dataset, axis1, axis2):
      """Swap two axes in a dataset"""
  
      data_py = dataset.active_scalars
      dataset.active_scalars = data_py.swapaxes(axis1, axis2)
  
new_contents: def transform(dataset, axis1, axis2):
      """Swap two axes in a dataset"""
  
      import numpy as np
  
      data_py = dataset.active_scalars
      swapped = data_py.swapaxes(axis1, axis2)
      dataset.active_scalars = np.asfortranarray(swapped)
  
subject: Convert array back to fortran before setting