if(USE_PYTHON)
   if(ENABLE_UNIT_TESTS)
     set(PYTHON_UNIT_TESTS TRUE)
     # check for prerequisite modules
     execute_process(COMMAND ${PYTHON_EXECUTABLE} -c "import pytest; print(pytest.__file__)"
       OUTPUT_VARIABLE pytest_path RESULT_VARIABLE pytest_result)
     if(NOT ${pytest_result} EQUAL 0)
       message(WARNING "python module 'pytest' not found.")
       set(PYTHON_UNIT_TESTS FALSE)
     endif()
     execute_process(COMMAND ${PYTHON_EXECUTABLE} -c "import pytest_check; print(pytest_check.__file__)"
       OUTPUT_VARIABLE pycheck_path RESULT_VARIABLE pycheck_result)
     if(NOT ${pytest_result} EQUAL 0)
       message(WARNING "python module 'pytest_check' not found.")
       set(PYTHON_UNIT_TESTS FALSE)
     endif()
     if(PYTHON_UNIT_TESTS)
       add_test(NAME pytest COMMAND ${PYTHON_EXECUTABLE} -m pytest WORKING_DIRECTORY ${CMAKE_CURRENT_SOURCE_DIR})
       add_custom_target(pytest ${PYTHON_EXECUTABLE} -m pytest WORKING_DIRECTORY ${CMAKE_CURRENT_SOURCE_DIR})
       set_tests_properties ( pytest PROPERTIES TIMEOUT 18000 )
       if(USE_MPI AND USE_MPI4PY)
	 add_test(NAME pytest-mpi COMMAND ${MPIEXEC_EXECUTABLE} --allow-run-as-root -np 4 ${PYTHON_EXECUTABLE} -m pytest --with-mpi test_mpi4py.py WORKING_DIRECTORY ${CMAKE_CURRENT_SOURCE_DIR})
       endif(USE_MPI AND USE_MPI4PY)
     else()
       message(WARNING "Unable to perform unit tests on netgen python modules.")
     endif()
   endif()
endif(USE_PYTHON)