def METHOD_NAME(self, node: SqlTimeDeltaExpression) -> SqlExpressionRenderResult:
    """Render time delta for BigQuery, which requires ISO prefixing for the WEEK granularity value."""
    column = node.arg.accept(self)
    if node.grain_to_date:
        granularity = node.granularity
        if granularity == TimeGranularity.WEEK:
            granularity_value = "ISO" + granularity.value.upper()
        else:
            granularity_value = granularity.value
        return SqlExpressionRenderResult(
            sql=f"DATE_TRUNC({column.sql}, {granularity_value})",
            bind_parameters=column.bind_parameters,
        )
    return SqlExpressionRenderResult(
        sql=f"DATE_SUB(CAST({column.sql} AS {self.timestamp_data_type}), INTERVAL {node.count} {node.granularity.value})",
        bind_parameters=column.bind_parameters,
    )