def __init__(self, num_parallel: int = 2, e2b_router_url: Optional[str] = None):
        """Initialize the E2B provider.

        Args:
            num_parallel: Number of parallel sandboxes to use
            e2b_router_url: URL for the E2B router (if using router mode)
        """
        if not is_e2b_available():
            raise ImportError(
                "E2B is not available and required for this provider. Please install E2B with "
                "`pip install e2b-code-interpreter` and add an API key to a `.env` file."
            )

        self.num_parallel = num_parallel
        self.e2b_router_url = e2b_router_url
Initialize the E2B provider.

        Args:
            num_parallel: Number of parallel sandboxes to use
            e2b_router_url: URL for the E2B router (if using router mode)
        
src/open_r1/utils/code_providers.py