pydantic_core._pydantic_core.ValidationError: 1 validation error for Choices
finish_reason
  Input should be 'stop', 'content_filter', 'function_call', 'tool_calls', 'length',
  'guardrail_intervened', 'eos', 'finish_reason_unspecified' or 'malformed_function_call'
  [type=literal_error, input_value='error', input_type=str]

litellm.APIConnectionError: OpenrouterException - Invalid response object

from pydantic import validator
from enum import Enum

class FinishReason(str, Enum):
    stop = "stop"
    content_filter = "content_filter"
    function_call = "function_call"
    tool_calls = "tool_calls"
    length = "length"
    guardrail_intervened = "guardrail_intervened"
    eos = "eos"
    finish_reason_unspecified = "finish_reason_unspecified"
    malformed_function_call = "malformed_function_call"
    error = "error"  # Add this line

class Choices(BaseModel):
    index: int
    finish_reason: FinishReason
    native_finish_reason: str
    message: Message

    @validator("finish_reason")
    def validate_finish_reason(cls, v):
        if v == "error":
            # Map "error" to an existing value or raise a custom exception
            raise litellm.BadRequestError("Invalid finish reason: error")
        return v

class BadRequestError(Exception):
    def __init__(self, message: str):
        self.message = message
        super().__init__(message)

try:
    response = Choices(**response_dict)
except litellm.BadRequestError as e:
    # Handle the exception and provide a clear error message
    raise litellm.APIConnectionError(f"OpenRouterException - {e.message}")