code: def _is_none(x):
      return x is None
  
file_path: equinox/equinox/_filters.py
imports: from collections.abc import Callable
  from typing import Any, Optional, Union
  import jax
  import jax.numpy
  import jax.tree_util
  import numpy
  from jaxtyping import PyTree
label_desc: Use image node_id 9 for calling a global function with example usage: _is_none(x) and returns: unknown