code: def test_execute_direct_sql_query_safe_query(self, mock_sql):
      safe_query = "SELECT * FROM users WHERE username = 'John'"
      expected_data = pd.DataFrame(
          {"Column1": [1, 2, 3], "Column2": [4, 5, 6]}
      )
      mock_sql.return_value = expected_data
      result = self.connector.execute_direct_sql_query(safe_query)
      assert isinstance(result, pd.DataFrame)
  
imports: import unittest
  import pandas
  from unittest.mock import Mock, patch
  from pandasai.connectors.base import SQLConnectorConfig
  from pandasai.connectors.sql import PostgreSQLConnector, SQLConnector
  from pandasai.exceptions import MaliciousQueryError
label_desc: Use image node_id 12 for calling the TestSQLConnector obj's underlying member method code with example usage: obj.test_execute_direct_sql_query_safe_query(mock_sql) without return types