*
     * @return the application type string, or empty string if not set
     */
    public static String getAppType() {
        final String appType = System.getenv(FESS_APP_TYPE);
        if (StringUtil.isNotBlank(appType)) {
            return appType;
        }
        return StringUtil.EMPTY;
    }

    /**
     * Gets the override configuration path from environment variable when running in Docker.

from starlette.routing import BaseRoute
from starlette.types import ASGIApp, ExceptionHandler, Lifespan, Receive, Scope, Send
from typing_extensions import deprecated

AppType = TypeVar("AppType", bound="FastAPI")


class FastAPI(Starlette):
    """
    `FastAPI` app class, the main entrypoint to use FastAPI.

    Read more in the

from starlette.routing import (
    BaseRoute,
    Match,
    compile_path,
    get_name,
)
from starlette.routing import Mount as Mount  # noqa
from starlette.types import AppType, ASGIApp, Lifespan, Receive, Scope, Send
from starlette.websockets import WebSocket
from typing_extensions import deprecated


# Copy of starlette.routing.request_response modified to include the