class_docstr: Simple agent that counts the number of unique things it has seen.
  
  Could be simpler, but we make it a TorchAgent so it's happy with dynamic batching.
class_docstr_tok: ["Simple","agent","that","counts","the","number","of","unique","things","it","has","seen",".","Could","be","simpler",",","but","we","make","it","a","TorchAgent","so","it","'s","happy","with","dynamic","batching","."]
code: def load(self, path=None):
      pass
  
imports: from __future__ import annotations
  from typing import Tuple
  from collections import Counter
  from parlai.core.torch_agent import TorchAgent
  from parlai.core.metrics import Metric, SumMetric
  from parlai.core.message import Message
label_desc: Use image node_id 4 for calling the CounterAgent obj's underlying member method code with example usage: obj.load(path) without return types