class_docstr: Cast observations to a given type.
  
  Args:
      env: Env to wrap.
      dtype: Data type object.
  
  Attributes:
      original_observation: Observation before casting.
code: def observation(self, observation):
      self.original_observation = observation
      return observation.astype(self.dtype, copy=False)
  
file_path: pfrl/pfrl/wrappers/cast_observation.py
imports: import gym
  import numpy
label_desc: Use image node_id 2 for calling the CastObservation obj's underlying member method code with example usage: obj.observation(observation) and returns: observation