class_docstr: `AgentBase` is the base class of the `parl.Agent` in different frameworks.
  
  `parl.Agent` is responsible for the general data flow outside the algorithm.
docstr: Sample the action when given the observation of the environment.
      
  In general, this function is used in train process.
  
  This function will usually do the following things:
     1. Accept numpy data as input;
     2. Feed numpy data or onvert numpy data to tensor (optional);
     3. Call predict or sample function in `Algorithm`;
     4. Add sampling operation in numpy level. (unnecessary if sampling operation have done in `Algorithm`).
code: def sample(self, *args, **kwargs):
      """Sample the action when given the observation of the environment.
  
      In general, this function is used in train process.
  
      This function will usually do the following things:
         1. Accept numpy data as input;
         2. Feed numpy data or onvert numpy data to tensor (optional);
         3. Call predict or sample function in `Algorithm`;
         4. Add sampling operation in numpy level. (unnecessary if sampling operation have done in `Algorithm`).
      """
      raise NotImplementedError
  
file_path: PARL/parl/core/agent_base.py
label_desc: Use image node_id 6 for calling the AgentBase obj's underlying member method code with example usage: obj.sample() without return types