code: def test_time_grain_expressions(
      dttm: str, grain: str, expected: str
  ) -> None:
      from superset.db_engine_specs.sqlite import SqliteEngineSpec
  
      engine = create_engine("sqlite://")
      connection = engine.connect()
      connection.execute("CREATE TABLE t (dttm DATETIME)")
      connection.execute("INSERT INTO t VALUES (?)", dttm)
  
      # pylint: disable=protected-access
      expression = SqliteEngineSpec._time_grain_expressions[
          grain
      ].format(col="dttm")
      sql = f"SELECT {expression} FROM t"
      result = connection.execute(sql).scalar()
      assert result == expected
  
file_path: superset/tests/unit_tests/db_engine_specs/test_sqlite.py
imports: from datetime import datetime
  from typing import Optional
  import pytest
  from sqlalchemy.engine import create_engine
  from superset.constants import TimeGrain
  from tests.unit_tests.db_engine_specs.utils import assert_convert_dttm
  from tests.unit_tests.fixtures.common import dttm
label_desc: Use image node_id 2 for calling a global function with example usage: test_time_grain_expressions(dttm, grain, expected) without return types