void HuntCrossleyForce::addGeometry(const std::string& name)
{
    if (get_contact_parameters().getSize()==0)
        updContactParametersSet().adoptAndAppend(
                new HuntCrossleyForce::ContactParameters());
    upd_contact_parameters()[0].addGeometry(name);
}
void HuntCrossleyForce::setStiffness(double stiffness) {
    if (get_contact_parameters().getSize()==0)
        updContactParametersSet().adoptAndAppend(
                new HuntCrossleyForce::ContactParameters());
    upd_contact_parameters()[0].setStiffness(stiffness); 
};
void HuntCrossleyForce::setViscousFriction(double friction) {
    if (get_contact_parameters().getSize()==0)
        updContactParametersSet().adoptAndAppend(
                new HuntCrossleyForce::ContactParameters());
    upd_contact_parameters()[0].setViscousFriction(friction); 
};
HuntCrossleyForce::ContactParametersSet& HuntCrossleyForce::
updContactParametersSet()
{
    return upd_contact_parameters();
}
ElasticFoundationForce::ContactParametersSet& ElasticFoundationForce::updContactParametersSet()
{
    return upd_contact_parameters();
}
void ElasticFoundationForce::addGeometry(const std::string& name)
{
    if (get_contact_parameters().getSize()==0)
            updContactParametersSet().adoptAndAppend(new ElasticFoundationForce::ContactParameters());
    upd_contact_parameters()[0].addGeometry(name);
}
void ElasticFoundationForce::setViscousFriction(double friction) {
        if (get_contact_parameters().getSize()==0)
            updContactParametersSet().adoptAndAppend(new ElasticFoundationForce::ContactParameters());
        upd_contact_parameters()[0].setViscousFriction(friction); 
};
void ElasticFoundationForce::setStiffness(double stiffness) {
        if (get_contact_parameters().getSize()==0)
            updContactParametersSet().adoptAndAppend(new ElasticFoundationForce::ContactParameters());
        upd_contact_parameters()[0].setStiffness(stiffness); 
};