code: def setup_method(self):
      self.connection = Connection(
          login="login",
          password="password",
          host="host",
          schema="database",
      )
  
      class UnitTestPostgresHook(PostgresHook):
          conn_name_attr = "test_conn_id"
  
      self.db_hook = UnitTestPostgresHook()
      self.db_hook.get_connection = mock.Mock()
      self.db_hook.get_connection.return_value = self.connection
  
imports: from __future__ import annotations
  import json
  import os
  from unittest import mock
  import psycopg2.extras
  import pytest
  from airflow.models import Connection
  from airflow.providers.postgres.hooks.postgres import PostgresHook
  from airflow.utils.types import NOTSET
label_desc: Use image node_id 1 for calling the TestPostgresHookConn obj's underlying member method code with example usage: obj.setup_method() without return types