code: def dims(self):
      return self.params.shape[-1]
  
imports: import warnings
  from typing import Callable, TypeVar
  import equinox
  from equinox import tree_equal
  from jax import eval_shape
  from jax import numpy
  from jax import vmap
  from jaxtyping import PyTree
  from jaxdf.core import Field
  from jaxdf.geometry import Domain
label_desc: Use image node_id 3 for calling the OnGrid obj's underlying member method code with example usage: obj.dims() and returns: self