docstr: Called when all decorators have been created for this flow.
code: def flow_init(
      self,
      flow,
      graph,
      environment,
      flow_datastore,
      metadata,
      logger,
      echo,
      options,
  ):
      """
      Called when all decorators have been created for this flow.
      """
      pass
  
imports: from functools import partial
  import json
  import re
  import os
  import sys
  from .flowspec import FlowSpec
  from .exception import MetaflowInternalError, MetaflowException, InvalidDecoratorAttribute
  from metaflow._vendor import click
label_desc: Use image node_id 2 for calling the FlowDecorator obj's underlying member method code with example usage: obj.flow_init(flow, graph, environment, flow_datastore, metadata, logger, echo, options) without return types