text: from fontTools.feaLib.error import FeatureLibError
  from fontTools.feaLib.location import FeatureLibLocation
  import unittest
  
  
  class FeatureLibErrorTest(unittest.TestCase):
      def test_str(self):
          err = FeatureLibError("Squeak!", FeatureLibLocation("foo.fea", 23, 42))
          self.assertEqual(str(err), "foo.fea:23:42: Squeak!")
  
      def test_str_nolocation(self):
          err = FeatureLibError("Squeak!", None)
          self.assertEqual(str(err), "Squeak!")
  
  
  if __name__ == "__main__":
      import sys
      sys.exit(unittest.main())
  