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