code: def unknown_signature(eqn, args_consumed):
      def is_key(var: core.Atom):
          return hasattr(var.aval, "dtype") and jax.dtypes.issubdtype(
              var.aval.dtype, jax.dtypes.prng_key
          )
  
      return KeyReuseSignature(
          sinks=[
              Sink(idx, True)
              for idx, var in enumerate(eqn.invars)
              if is_key(var)
          ],
          sources=[],
      )
  
imports: from __future__ import annotations
  from collections import defaultdict
  from functools import reduce
  from typing import Any, Callable
  import jax
  from jax import core
  from jax import lax
  from jax import tree_util
  from jax._src import api_util
  from jax._src import linear_util
  from jax._src import pjit
  from jax._src import prng
  from jax._src import random
  from jax._src import util
  from jax._src.debugging import debug_callback_p
  from jax._src.interpreters import partial_eval
  from jax.experimental.key_reuse._common import consume_p, unconsumed_copy_p, assert_consumed_value_p, KeyReuseError, Sink, Source, KeyReuseSignature
  import numpy
label_desc: Use image node_id 1 for calling a global function with example usage: unknown_signature(eqn, args_consumed) and returns: KeyReuseSignature, unknown