code: def _handle_tree(chunk):
      op = NE_TREE_OP_TO_STRING[type(chunk.op)]
      return op.join(f"{{{c.key}}}" for c in chunk.inputs)
  
imports: from collections import defaultdict
  from itertools import count
  import numpy
  from ..operands import TensorFuse
  from ..None import arithmetic, reduction
  from ..array_utils import as_same_device
  from .core import TensorFuseChunkMixin
label_desc: Use image node_id 4 for calling a global function with example usage: _handle_tree(chunk) and returns: op