declare const checkTypes: readonly ['Array', 'AbortSignal', 'AbortController', 'String', 'Function', 'AsyncFunction', 'Number', 'Boolean', 'Symbol', 'Null', 'Promise'];
declare const specialCheckFunctions: {
    Date: (value: unknown) => boolean;
    Object: typeof isObject;
    Headers: typeof isHeaders;
};
type CheckFunctions = typeof specialCheckFunctions & {
    [checkType in typeof checkTypes[number]]: (value: unknown) => boolean;
};
declare const checkFunctions: CheckFunctions;
declare function isObject(income: unknown): income is Record<string | number | symbol, unknown>;
declare function isHeaders(income: unknown): income is Headers;
export { checkFunctions as is };