old_contents: 
  from switch        import switch
  from bunch         import Bunch        as bunch
  from ordered_bunch import OrderedBunch as ordered_bunch
  from plot          import write_plot, tecplot, paraview
  from lhc_unif      import lhc_unif
  from mp_eval       import mp_eval
new_contents: from switch        import switch
  from bunch         import Bunch        as bunch
  from ordered_bunch import OrderedBunch as ordered_bunch
  from plot          import write_plot, tecplot, paraview
  from lhc_unif      import lhc_unif
  from mp_eval       import mp_eval
  from which         import which
  
subject: Update __init__.py