import type * as RDF from '@rdfjs/types';
import type { BooleanValueNode } from 'graphql/language';
import type { IConvertContext } from '../../IConvertContext';
import type { IConvertSettings } from '../../IConvertSettings';
import type { Util } from '../../Util';
import type { IValueNodeHandlerOutput } from './NodeValueHandlerAdapter';
import { NodeValueHandlerAdapter } from './NodeValueHandlerAdapter';
/**
 * Converts GraphQL booleans to RDF boolean terms.
 */
export declare class NodeValueHandlerBoolean extends NodeValueHandlerAdapter<BooleanValueNode> {
    protected readonly datatype: RDF.NamedNode;
    constructor(util: Util, settings: IConvertSettings);
    handle(valueNode: BooleanValueNode, _fieldName: string, _convertContext: IConvertContext): IValueNodeHandlerOutput;
}