doxygen_add_docs(
  Documentation ${ITK_DOXYGEN_INPUT}
  # -- Only build if 'Documentation' target is requested ALL
  WORKING_DIRECTORY ${ITK_BINARY_DIR}/Utilities/Doxygen
  # -- Some of the ITK_DOXYGEN_INPUT are directories, USE_STAMP_FILE requires only files be listed
  COMMENT "-- Building ITK Doxygen.")

doxygen_add_docs(
  ${WRAPPER_LIBRARY_NAME}Doxygen ${ITK_WRAP_DOC_DOXYGEN_HEADERS} ALL
  WORKING_DIRECTORY ${ITK_WRAP_DOC_LIBRARY_DIR} USE_STAMP_FILE
  COMMENT "-- Wrapping library ${WRAPPER_LIBRARY_NAME}: Constructing documentation xml structure.")