def __init__(
        self,
        github_token: Optional[str] = None,
        base_url: str = DEFAULT_BASE_URL,
        api_version: str = DEFAULT_API_VERSION,
        verbose: bool = False,
    ) -> None:
        """
        Initialize the GitHubIssuesClient.

        Args:
            - github_token (str): GitHub token for authentication.
                If not provided, the client will try to get it from
                the GITHUB_TOKEN environment variable.
            - base_url (str): Base URL for the GitHub API
                (defaults to "https://api.github.com").
            - api_version (str): GitHub API version (defaults to "2022-11-28").

        Raises:
            ValueError: If no GitHub token is provided.

        """
        if github_token is None:
            github_token = os.getenv("GITHUB_TOKEN")
            if github_token is None:
                raise ValueError(
                    "Please provide a GitHub token. "
                    + "You can do so by passing it as an argument to the GitHubReader,"
                    + "or by setting the GITHUB_TOKEN environment variable."
                )

        self._base_url = base_url
        self._api_version = api_version
        self._verbose = verbose

        self._endpoints = {
            "getIssues": "/repos/{owner}/{repo}/issues",
        }

        self._headers = {
            "Accept": "application/vnd.github+json",
            "Authorization": f"Bearer {github_token}",
            "X-GitHub-Api-Version": f"{self._api_version}",
        }

        Initialize the GitHubIssuesClient.

        Args:
            - github_token (str): GitHub token for authentication.
                If not provided, the client will try to get it from
                the GITHUB_TOKEN environment variable.
            - base_url (str): Base URL for the GitHub API
                (defaults to "https://api.github.com").
            - api_version (str): GitHub API version (defaults to "2022-11-28").

        Raises:
            ValueError: If no GitHub token is provided.

        
llama-index-integrations/readers/llama-index-readers-github/llama_index/readers/github/issues/github_client.py