text: from unittest import TestCase
  
  from rest_framework.exceptions import ValidationError
  
  from life.utils.serializer.phonenumber_ispossible_field import PhoneNumberIsPossibleField
  
  
  class TestPhoneNumberIsPossibleField(TestCase):
      def test_phone_number(self):
          # map -> input value -> output value
          # if output value is None, the it is invalid
  
          test_cases = {
              "7795937091": "+917795937091",
              "07795937091": "+917795937091",
              "+917795937091": "+917795937091",
              "+1 470-485-8757": "+14704858757",
              "+18944775567": "+18944775567",
              "+911234": None,
          }
  
          for ip, op in test_cases.items():
              if op is None:
                  with self.assertRaises(ValidationError):
                      PhoneNumberIsPossibleField().to_internal_value(ip)
              else:
                  self.assertEqual(PhoneNumberIsPossibleField().to_internal_value(ip), op)
  