dispatch(opts, handler) {
        const headers = buildHeaders(opts.headers);
        throwIfProxyAuthIsSent(headers);
        if (headers && !("host" in headers) && !("Host" in headers)) {
          const { host } = new URL2(opts.origin);
          headers.host = host;
        }
        return this[kAgent].dispatch(
          {
            ...opts,
            headers
          },
          handler
        );
      }
@param {import('../types/proxy-agent').ProxyAgent.Options | string | URL} opts
@returns {URL}