code: def chain_as_grid(*tasks: BashOperator):
      """
      Chain tasks as a grid:
  
       t0 -> t1 -> t2 -> t3
        |     |     |
        v     v     v
       t4 -> t5 -> t6
        |     |
        v     v
       t7 -> t8
        |
        v
       t9
      """
      if len(tasks) > 100 * 99 / 2:
          raise ValueError(
              "Cannot generate grid DAGs with lateral size larger than 100 tasks."
          )
      grid_size = next(
          n for n in range(100) if n * (n + 1) / 2 >= len(tasks)
      )
  
      def index(i, j):
          """
          Return the index of node (i, j) on the grid.
          """
          return int(grid_size * i - i * (i - 1) / 2 + j)
  
      for i in range(grid_size - 1):
          for j in range(grid_size - i - 1):
              if index(i + 1, j) < len(tasks):
                  tasks[index(i + 1, j)].set_downstream(
                      tasks[index(i, j)]
                  )
              if index(i, j + 1) < len(tasks):
                  tasks[index(i, j + 1)].set_downstream(
                      tasks[index(i, j)]
                  )
  
file_path: airflow/dev/perf/dags/elastic_dag.py
imports: from __future__ import annotations
  import enum
  import os
  import re
  from datetime import datetime, timedelta
  from enum import Enum
  from airflow.models.baseoperator import chain
  from airflow.models.dag import DAG
  from airflow.operators.bash import BashOperator
label_desc: Use image node_id 5 for calling a global function with example usage: chain_as_grid() and returns: int