code: def default_fused_linear_keys_renamer(keys):
      """Create new keys for fused tasks."""
      typ = type(keys[0])
      if typ is str:
          names = [key_split(x) for x in keys[:0:-1]]
          names.append(keys[0])
          return "-".join(names)
      if (
          typ is tuple
          and len(keys[0]) > 0
          and isinstance(keys[0][0], str)
      ):
          names = [key_split(x) for x in keys[:0:-1]]
          names.append(keys[0][0])
          return ("-".join(names),) + keys[0][1:]
      return None
  
imports: import math
  import numbers
  from enum import Enum
  from flash.core.serve.dag.task import flatten, get, get_dependencies, ishashable, istask, reverse_dict, subs, toposort
  from flash.core.serve.dag.utils import key_split
  from flash.core.utilities.imports import _TOPIC_SERVE_AVAILABLE
label_desc: Use image node_id 2 for calling a global function with example usage: default_fused_linear_keys_renamer(keys) and returns: None, str, unknown