code: def _decompose(chunk):
      expr = f"{{{chunk.key}}}"
      for node in reversed(chunk.composed):
          _expr = _evaluate(node)
          expr = expr.format_map(_Default([(node.key, f"({_expr})")]))
      return expr
  
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 2 for calling a global function with example usage: _decompose(chunk) and returns: expr