class_docstr: ActionValue that can evaluate only a single action.
class_docstr_tok: ["ActionValue","that","can","evaluate","only","a","single","action","."]
code: def params(self):
      warnings.warn(
          "SingleActionValue has no learnable parameters until it"
          " is evaluated on some action. If you want to draw a computation"
          " graph that outputs SingleActionValue, use the variable returned"
          " by its method such as evaluate_actions instead."
      )
      return ()
  
imports: import warnings
  from abc import ABCMeta, abstractmethod, abstractproperty
  import torch
  import torch.nn.functional
  from torch.distributions.utils import lazy_property
label_desc: Use image node_id 8 for calling the SingleActionValue obj's underlying member method code with example usage: obj.params() and returns: 