code: def combine(
      *pytrees: PyTree, is_leaf: Optional[Callable[[Any], bool]] = None
  ) -> PyTree:
      """Combines multiple PyTrees into one PyTree, by replacing `None` leaves.
  
      !!! example
  
          ```python
          pytree1 = [None, 1, 2]
          pytree2 = [0, None, None]
          equinox.combine(pytree1, pytree2)  # [0, 1, 2]
          ```
  
      !!! tip
  
          The idea is that `equinox.combine` should be used to undo a call to
          [`equinox.filter`][] or [`equinox.partition`][].
  
      **Arguments:**
  
      - `*pytrees`: a sequence of PyTrees all with the same structure.
      - `is_leaf`: As [`equinox.partition`][].
  
      **Returns:**
  
      A PyTree with the same structure as its inputs. Each leaf will be the first
      non-`None` leaf found in the corresponding leaves of `pytrees` as they are
      iterated over.
      """
      if is_leaf is None:
          _is_leaf = _is_none
      else:
          _is_leaf = lambda x: _is_none(x) or is_leaf(x)
  
      return jtu.tree_map(_combine, *pytrees, is_leaf=_is_leaf)
  
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 10 for calling a global function with example usage: combine() and returns: jtu