class_docstr: Interface for an agent that can act.
  
  This interface defines an API for an Actor to interact with an EnvironmentLoop
  (see acme.environment_loop), e.g. a simple RL loop where each step is of the
  form:
  
    # Make the first observation.
    timestep = env.reset()
    actor.observe_first(timestep)
  
    # Take a step and observe.
    action = actor.select_action(timestep.observation)
    next_timestep = env.step(action)
    actor.observe(action, next_timestep)
  
    # Update the actor policy/parameters.
    actor.update()
class_docstr_tok: ["Interface","for","an","agent","that","can","act",".","This","interface","defines","an","API","for","an","Actor","to","interact","with","an","EnvironmentLoop","(","see","acme.environment_loop",")",",","e.g",".","a","simple","RL","loop","where","each","step","is","of","the","form",":","#","Make","the","first","observation",".","timestep","=","env.reset","(",")","actor.observe_first","(","timestep",")","#","Take","a","step","and","observe",".","action","=","actor.select_action","(","timestep.observation",")","next_timestep","=","env.step","(","action",")","actor.observe","(","action",",","next_timestep",")","#","Update","the","actor","policy\/parameters",".","actor.update","(",")"]
docstr: Perform an update of the actor parameters from past observations.
  
  Args:
    wait: if True, the update will be blocking.
docstr_tok: ["Perform","an","update","of","the","actor","parameters","from","past","observations",".","Args",":","wait",":","if","True",",","the","update","will","be","blocking","."]
code: def update(self, wait: bool = False):
      """Perform an update of the actor parameters from past observations.
  
      Args:
        wait: if True, the update will be blocking.
      """
  
imports: import abc
  import itertools
  from typing import Generic, Iterator, List, Optional, Sequence, TypeVar
  from acme import types
  from acme.utils import metrics
  import dm_env
label_desc: Use image node_id 4 for calling the Actor obj's underlying member method code with example usage: obj.update(wait) without return types