text: from unittest import TestCase
  
  from piccolo.engine.postgres import PostgresEngine
  from ..base import postgres_only
  
  
  @postgres_only
  class TestVersionParsing(TestCase):
      def test_version_parsing(self):
          """
          Make sure the version number can correctly be parsed from a range
          of known formats.
          """
          self.assertEqual(
              PostgresEngine._parse_raw_version_string(version_string="9.4"), 9.4
          )
  
          self.assertEqual(
              PostgresEngine._parse_raw_version_string(version_string="9.4.1"),
              9.4,
          )
  
          self.assertEqual(
              PostgresEngine._parse_raw_version_string(
                  version_string="12.4 (Ubuntu 12.4-0ubuntu0.20.04.1)"
              ),
              12.4,
          )
  