code: def test_date_trunc_to_quarter(
      sql_client: SqlClient, input: str, expected: pd.Timestamp
  ) -> None:
      """Tests default date trunc behavior to quarterly boundaries.
  
      This should generally pin to the first day of the "natural" yearly quarters, for example,
      2015-01-01, 2015-04-01, 2015-07-01, and 2015-10-01.
      """
      date_trunc_stmt = sql_client.sql_query_plan_renderer.expr_renderer.render_sql_expr(
          _build_date_trunc_expression(
              date_string=input,
              time_granularity=TimeGranularity.QUARTER,
          )
      ).sql
  
      df = sql_client.query(f"SELECT {date_trunc_stmt}")
  
      actual = pd.Timestamp(_extract_dataframe_value(df=df))
      assert expected == actual
  
file_path: metricflow/metricflow/test/sql_clients/test_date_time_operations.py
imports: from __future__ import annotations
  import logging
  from typing import Any
  import pandas
  import pytest
  from dbt_semantic_interfaces.type_enums.date_part import DatePart
  from metricflow.protocols.sql_client import SqlClient
  from metricflow.sql.sql_exprs import SqlCastToTimestampExpression, SqlDateTruncExpression, SqlExtractExpression, SqlStringLiteralExpression
  from metricflow.time.time_granularity import TimeGranularity
label_desc: Use image node_id 4 for calling a global function with example usage: test_date_trunc_to_quarter(sql_client, input, expected) without return types