old_contents: from ._fisx import PySimpleIni as SimpleIni
  from ._fisx import PySimpleSpecfile as SimpleSpecfile
  from ._fisx import PyEPDL97 as EPDL97
  from ._fisx import PyShell as Shell
  from ._fisx import PyElement as Element
  from ._fisx import PyElements as Elements
  from ._fisx import PyLayer as Layer
  from ._fisx import PyXRF as XRF
  
new_contents: from ._fisx import PySimpleIni as SimpleIni
  from ._fisx import PySimpleSpecfile as SimpleSpecfile
  from ._fisx import PyEPDL97 as EPDL97
  from ._fisx import PyShell as Shell
  from ._fisx import PyElement as Element
  from ._fisx import PyElements as Elements
  from ._fisx import PyLayer as Layer
  from ._fisx import PyDetector as Detector
  from ._fisx import PyXRF as XRF
  
subject: Add detector class.