import { Connection, AddTokenOptions } from '../types';
export declare class MetaMaskConnection extends Connection {
    protected static _instance: MetaMaskConnection;
    static getInstance(): MetaMaskConnection;
    private eagerConnection;
    private ethereum;
    private constructor();
    private _initialize;
    initialize(): Promise<void>;
    connect(): Promise<import("../types").ConnectionState>;
    switchChain(chainId: number): Promise<void>;
    addToken(options: AddTokenOptions): Promise<void>;
    disconnect(error?: any): Promise<void>;
}