_tiedProperties.Tie("level-kg", this, &TankProperties::getContent_kg, &TankProperties::setContent_kg );
_tiedProperties.Tie("density-kgpm3", this, &TankProperties::getDensity_kgpm3, &TankProperties::setDensity_kgpm3 );
_tiedProperties.Tie("capacity-m3", this, &TankProperties::getCapacity_m3, &TankProperties::setCapacity_m3 );
_tiedProperties.Tie("level-kg", this, &TankProperties::getContent_kg, &TankProperties::setContent_kg );
_tiedProperties.Tie("density-kgpm3", this, &TankProperties::getDensity_kgpm3, &TankProperties::setDensity_kgpm3 );
_tiedProperties.Tie("capacity-m3", this, &TankProperties::getCapacity_m3, &TankProperties::setCapacity_m3 );