code: def histogram(
      jaxpr: core.Jaxpr, key: Callable, key_fmt: Callable = lambda x: x
  ):
      d = collect_eqns(jaxpr, key)
      return {key_fmt(k): len(v) for k, v in d.items()}
  
imports: from __future__ import annotations
  from collections import Counter, defaultdict
  import gzip
  import itertools
  import json
  import types
  from typing import Any, Callable, Union
  from jax._src import core
  from jax._src import util
  from jax._src import source_info_util
  from jax._src.lib import xla_client
label_desc: Use image node_id 3 for calling a global function with example usage: histogram(jaxpr, key, key_fmt) and returns: unknown