code: def test_is_sql_query_safe_safe_query(self):
      safe_query = "SELECT * FROM users WHERE username = 'John'"
      result = self.connector._is_sql_query_safe(safe_query)
      assert result is True
  
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 10 for calling the TestSQLConnector obj's underlying member method code with example usage: obj.test_is_sql_query_safe_safe_query() without return types