code: def test_estimate_statement_cost(self):
      mock_cursor = mock.MagicMock()
      estimate_json = {"a": "b"}
      mock_cursor.fetchone.return_value = [
          '{"a": "b"}',
      ]
      result = PrestoEngineSpec.estimate_statement_cost(
          "SELECT * FROM brth_names", mock_cursor
      )
      assert result == estimate_json
  
imports: from collections import namedtuple
  from textwrap import dedent
  from unittest import mock, skipUnless
  import pandas
  from flask.ctx import AppContext
  from sqlalchemy import types
  from sqlalchemy.sql import select
  from superset.db_engine_specs.presto import PrestoEngineSpec
  from superset.errors import ErrorLevel, SupersetError, SupersetErrorType
  from superset.sql_parse import ParsedQuery
  from superset.utils.database import get_example_database
  from tests.integration_tests.db_engine_specs.base_tests import TestDbEngineSpec
label_desc: Use image node_id 30 for calling the TestPrestoDbEngineSpec obj's underlying member method code with example usage: obj.test_estimate_statement_cost() without return types