if !mptcp {
		t.Error("outgoing connection is not with MPTCP")
	}

	// Also check the method for the older kernels if not tested before
	if hasSOLMPTCP && !isUsingMPTCPProto(tcp.fd) {
		t.Error("outgoing connection is not an MPTCP proto")
	}
}

func canCreateMPTCPSocket() bool {
	// We want to know if we can create an MPTCP socket, not just if it is

	// system. But also fallback in case of any error with MPTCP.
	//
	// Possible MPTCP specific error: ENOPROTOOPT (sysctl net.mptcp.enabled=0)
	// But just in case MPTCP is blocked differently (SELinux, etc.), just
	// retry with "plain" TCP.
	return sl.listenTCP(ctx, laddr)
}

// hasFallenBack reports whether the MPTCP connection has fallen back to "plain"
// TCP.
//

	KeepAliveConfig KeepAliveConfig

	// If mptcpStatus is set to a value allowing Multipath TCP (MPTCP) to be
	// used, any call to Listen with "tcp(4|6)" as network will use MPTCP if
	// supported by the operating system.
	mptcpStatus mptcpStatus
}

// MultipathTCP reports whether MPTCP will be used.
//
// This method doesn't check if MPTCP is supported by the operating
// system or not.
func (lc *ListenConfig) MultipathTCP() bool {

	}
	return nil
}

// MultipathTCP reports whether the ongoing connection is using MPTCP.
//
// If Multipath TCP is not supported by the host, by the other peer or
// intentionally / accidentally filtered out by a device in between, a
// fallback to TCP will be done. This method does its best to check if
// MPTCP is still being used or not.
//
// On Linux, more conditions are verified on kernels >= v5.16, improving