text: from unittest import TestCase
  
  from tailow.operators.base import Q, transform_query
  from tailow.fields import ListField, IntegerField
  from tailow.operators.size import SizeOperator
  
  
  class TestOperators(TestCase):
  
      def setUp(self):
          self._fields = {
              "tags": ListField(sub_field=IntegerField())
          }
          self.size = SizeOperator()
  
      def test_operator_behaviours(self):
          """ test operator behaviour """
          val = self.size.to_query("tags", [1,2,3,4])
          self.assertDictEqual(val, {
              "$size": [1,2,3,4]
          })