text: import unittest
  import polyhedral_analysis.utils as utils
  
  class TestUtilsFunctions( unittest.TestCase ):
  
      def test_flatten( self ):
          nested = [ [ 1, 2, 3 ], [ 4, 5, 6 ] ]
          flat = [ 1, 2, 3, 4, 5, 6 ]
          self.assertEqual( flat, utils.flatten( nested ) )
  
  if __name__ == '__main__':
      unittest.main()
  