class_docstr: Wraps a callable (e.g. an activation function) for use with
  [`equinox.nn.Sequential`][].
  
  Precisely, this just adds an extra `key` argument (that is ignored). Given some
  function `fn`, then `Lambda` is essentially a convenience for `lambda x, key: f(x)`.
  
  !!! faq
  
      If you get a TypeError saying the function is not a valid JAX type, see the
          [FAQ](https://docs.kidger.site/equinox/faq/).
  
  !!! Example
  
      ```python
         model = eqx.nn.Sequential(
             [
                 eqx.nn.Linear(...),
                 eqx.nn.Lambda(jax.nn.relu),
                 ...
             ]
         )
      ```
docstr: **Arguments:**
  
  - `x`: The input JAX array.
  - `key`: Ignored.
  
  **Returns:**
  
  The output of the `fn(x)` operation.
docstr_tok: ["*","*","Arguments",":","*","*","-","`","x","`",":","The","input","JAX","array",".","-","`","key","`",":","Ignored",".","*","*","Returns",":","*","*","The","output","of","the","`","fn","(","x",")","`","operation","."]
code: def __call__(
      self, x: Array, *, key: Optional[PRNGKeyArray] = None
  ) -> Array:
      """**Arguments:**
  
      - `x`: The input JAX array.
      - `key`: Ignored.
  
      **Returns:**
  
      The output of the `fn(x)` operation.
      """
      return self.fn(x)
  
imports: from collections.abc import Callable, Sequence
  from typing import Any, Optional, overload, Union
  import jax
  import jax.random
  from jaxtyping import Array, PRNGKeyArray
  from .._better_abstract import AbstractClassVar
  from .._custom_types import sentinel
  from .._module import Module, StrictConfig
  from ._stateful import State
label_desc: Use image node_id 1 for calling the Lambda obj's underlying member method code with example usage: obj.__call__(x) and returns: self