old_contents: from em_examples.DCLayers import *
  from em_examples.DC_Pseudosections import *
  from em_examples.DC_cylinder import *
  
new_contents: from em_examples.DCLayers import plot_layer_potentials_app
  from em_examples.DC_Pseudosections import MidpointPseudoSectionWidget, DC2DPseudoWidget, DC2DfwdWidget
  from em_examples.DC_cylinder import cylinder_app
  
subject: fix import