text: import unittest
  
  from django_nlf import DjangoNLFLanguage, LanguageSyntaxError
  
  
  class DjangoNLFListenerSingleExpressionTestCase(unittest.TestCase):
      def setUp(self):
          self.nl_filter = DjangoNLFLanguage()
  
      def test_invalid_lookups(self):
          expressions = ["space in filed name equals value", "field in"]
          for expr in expressions:
              with self.assertRaises(LanguageSyntaxError):
                  self.nl_filter.parse(expr)
  