/**
 * Transport layer interface expected by the user agent core.
 *
 * @remarks
 * The transport layer is responsible for the actual transmission of
 * requests and responses over network transports.  This includes
 * determination of the connection to use for a request or response in
 * the case of connection-oriented transports.
 * https://tools.ietf.org/html/rfc3261#section-18
 *
 * @public
 */
export interface Transport {
    /**
     * The transport protocol.
     *
     * @remarks
     * Formatted as defined for the Via header sent-protocol transport.
     * https://tools.ietf.org/html/rfc3261#section-20.42
     */
    readonly protocol: string;
    /**
     * Send a message.
     *
     * @remarks
     * Resolves once message is sent. Otherwise rejects with an Error.
     *
     * @param message - Message to send.
     */
    send(message: string): Promise<void>;
}