import { BlankNode, DefaultGraph, Literal, NamedNode } from "@rdfjs/types";
import { ObjectType } from "../types";
export declare function nodeToString(node: NamedNode | BlankNode | DefaultGraph | Literal | null | undefined): string;
export declare class NodeSet {
    private set;
    private map;
    add(node: ObjectType): void;
    has(node: ObjectType): boolean;
    delete(node: ObjectType): boolean;
    toArray(): ObjectType[];
}