default boolean discoverInternal(int s) {
        IConnectable c = getInternal(s);
        if (c != null) {
            return canConnectPart(c, s) && c.connectInternal(this, -1);
        }
        return discoverInternalOverride(s);
    }
Returns true if nothing is blocking a connection to an external part on side s
core/src/main/java/mrtjp/projectred/core/part/IConnectableCenterPart.java