void CustomNonbondedForceProxy::serialize(const void* object, SerializationNode& node) const {
    node.setIntProperty("version", 2);
    const CustomNonbondedForce& force = *reinterpret_cast<const CustomNonbondedForce*>(object);
    node.setIntProperty("forceGroup", force.getForceGroup());
    node.setStringProperty("energy", force.getEnergyFunction());
    node.setIntProperty("method", (int) force.getNonbondedMethod());
    node.setDoubleProperty("cutoff", force.getCutoffDistance());
    node.setBoolProperty("useSwitchingFunction", force.getUseSwitchingFunction());
    node.setDoubleProperty("switchingDistance", force.getSwitchingDistance());
    node.setBoolProperty("useLongRangeCorrection", force.getUseLongRangeCorrection());
    SerializationNode& perParticleParams = node.createChildNode("PerParticleParameters");
    for (int i = 0; i < force.getNumPerParticleParameters(); i++) {
        perParticleParams.createChildNode("Parameter").setStringProperty("name", force.getPerParticleParameterName(i));
    }
    SerializationNode& globalParams = node.createChildNode("GlobalParameters");
    for (int i = 0; i < force.getNumGlobalParameters(); i++) {
        globalParams.createChildNode("Parameter").setStringProperty("name", force.getGlobalParameterName(i)).setDoubleProperty("default", force.getGlobalParameterDefaultValue(i));
    }
    SerializationNode& energyDerivs = node.createChildNode("EnergyParameterDerivatives");
    for (int i = 0; i < force.getNumEnergyParameterDerivatives(); i++) {
        energyDerivs.createChildNode("Parameter").setStringProperty("name", force.getEnergyParameterDerivativeName(i));
    }
    SerializationNode& particles = node.createChildNode("Particles");
    for (int i = 0; i < force.getNumParticles(); i++) {
        vector<double> params;
        force.getParticleParameters(i, params);
        SerializationNode& node = particles.createChildNode("Particle");
        for (int j = 0; j < (int) params.size(); j++) {
            stringstream key;
            key << "param";
            key << j+1;
            node.setDoubleProperty(key.str(), params[j]);
        }
    }
    SerializationNode& exclusions = node.createChildNode("Exclusions");
    for (int i = 0; i < force.getNumExclusions(); i++) {
        int particle1, particle2;
        force.getExclusionParticles(i, particle1, particle2);
        exclusions.createChildNode("Exclusion").setIntProperty("p1", particle1).setIntProperty("p2", particle2);
    }
    SerializationNode& functions = node.createChildNode("Functions");
    for (int i = 0; i < force.getNumTabulatedFunctions(); i++)
        functions.createChildNode("Function", &force.getTabulatedFunction(i)).setStringProperty("name", force.getTabulatedFunctionName(i));

    SerializationNode& interactionGroups = node.createChildNode("InteractionGroups");
    for (int i = 0; i < force.getNumInteractionGroups(); i++) {
        SerializationNode& interactionGroup = interactionGroups.createChildNode("InteractionGroup");
        std::set<int> set1;
        std::set<int> set2;
        force.getInteractionGroupParameters(i, set1, set2);
        SerializationNode& set1node = interactionGroup.createChildNode("Set1");
        for (std::set<int>::iterator it = set1.begin(); it != set1.end(); ++it)
            set1node.createChildNode("Particle").setIntProperty("index", *it);
        SerializationNode& set2node = interactionGroup.createChildNode("Set2");
        for (std::set<int>::iterator it = set2.begin(); it != set2.end(); ++it)
            set2node.createChildNode("Particle").setIntProperty("index", *it);
    }
}
void CustomBondForceProxy::serialize(const void* object, SerializationNode& node) const {
    node.setIntProperty("version", 3);
    const CustomBondForce& force = *reinterpret_cast<const CustomBondForce*>(object);
    node.setIntProperty("forceGroup", force.getForceGroup());
    node.setBoolProperty("usesPeriodic", force.usesPeriodicBoundaryConditions());
    node.setStringProperty("energy", force.getEnergyFunction());
    SerializationNode& perBondParams = node.createChildNode("PerBondParameters");
    for (int i = 0; i < force.getNumPerBondParameters(); i++) {
        perBondParams.createChildNode("Parameter").setStringProperty("name", force.getPerBondParameterName(i));
    }
    SerializationNode& globalParams = node.createChildNode("GlobalParameters");
    for (int i = 0; i < force.getNumGlobalParameters(); i++) {
        globalParams.createChildNode("Parameter").setStringProperty("name", force.getGlobalParameterName(i)).setDoubleProperty("default", force.getGlobalParameterDefaultValue(i));
    }
    SerializationNode& energyDerivs = node.createChildNode("EnergyParameterDerivatives");
    for (int i = 0; i < force.getNumEnergyParameterDerivatives(); i++) {
        energyDerivs.createChildNode("Parameter").setStringProperty("name", force.getEnergyParameterDerivativeName(i));
    }
    SerializationNode& bonds = node.createChildNode("Bonds");
    for (int i = 0; i < force.getNumBonds(); i++) {
        int p1, p2;
        vector<double> params;
        force.getBondParameters(i, p1, p2, params);
        SerializationNode& node = bonds.createChildNode("Bond").setIntProperty("p1", p1).setIntProperty("p2", p2);
        for (int j = 0; j < (int) params.size(); j++) {
            stringstream key;
            key << "param";
            key << j+1;
            node.setDoubleProperty(key.str(), params[j]);
        }
    }
}
void GayBerneForceProxy::serialize(const void* object, SerializationNode& node) const {
    node.setIntProperty("version", 1);
    const GayBerneForce& force = *reinterpret_cast<const GayBerneForce*>(object);
    node.setIntProperty("forceGroup", force.getForceGroup());
    node.setIntProperty("method", (int) force.getNonbondedMethod());
    node.setDoubleProperty("cutoff", force.getCutoffDistance());
    node.setBoolProperty("useSwitchingFunction", force.getUseSwitchingFunction());
    node.setDoubleProperty("switchingDistance", force.getSwitchingDistance());
    SerializationNode& particles = node.createChildNode("Particles");
    for (int i = 0; i < force.getNumParticles(); i++) {
        double sigma, epsilon, sx, sy, sz, ex, ey, ez;
        int xparticle, yparticle;
        force.getParticleParameters(i, sigma, epsilon, xparticle, yparticle, sx, sy, sz, ex, ey, ez);
        particles.createChildNode("Particle").setDoubleProperty("sig", sigma).setDoubleProperty("eps", epsilon).setDoubleProperty("sx", sx)
                .setDoubleProperty("sy", sy).setDoubleProperty("sz", sz).setDoubleProperty("ex", ex).setDoubleProperty("ey", ey).setDoubleProperty("ez", ez)
                .setIntProperty("xparticle", xparticle).setIntProperty("yparticle", yparticle);
    }
    SerializationNode& exceptions = node.createChildNode("Exceptions");
    for (int i = 0; i < force.getNumExceptions(); i++) {
        int particle1, particle2;
        double sigma, epsilon;
        force.getExceptionParameters(i, particle1, particle2, sigma, epsilon);
        exceptions.createChildNode("Exception").setIntProperty("p1", particle1).setIntProperty("p2", particle2).setDoubleProperty("sig", sigma).setDoubleProperty("eps", epsilon);
    }
}