docstr: The prefix token. Cohere does not return the log prob for the first token when `echo_prompt` is True.
docstr_tok: ["The","prefix","token",".","Cohere","does","not","return","the","log","prob","for","the","first","token","when","`","echo_prompt","`","is","True","."]
code: def prefix_token(self) -> str:
      """
      The prefix token. Cohere does not return the log prob for the first token when `echo_prompt` is True.
      """
      # Cohere recommended ":", but we can try out different values
      return ":"
  
imports: from typing import List, Optional
  from helm.proxy.clients.cohere_client import CohereClient
  from .local_window_service import LocalWindowService
  from .tokenizer_service import TokenizerService
  from .window_service import EncodeResult
  from helm.common.tokenization_request import TokenizationRequest, TokenizationRequestResult, TokenizationToken
label_desc: Use image node_id 6 for calling the CohereWindowService obj's underlying member method code with example usage: obj.prefix_token() and returns: str