public static Density From(Mass m, Volume v)
 {
     return(new Density(m, v));
 }
 public Density(SerializationInfo info, StreamingContext context)
 {
     _mass   = (Mass)info.GetValue(MassSerializedFieldName, typeof(Mass));
     _volume = (Volume)info.GetValue(VolumeSerializedFieldName, typeof(Volume));
 }
 /////////////////////////////////////////////////////////////////////////////
 // BOXING
 /////////////////////////////////////////////////////////////////////////////
 public Density(Mass m, Volume v)
 {
     _mass   = m;
     _volume = v;
 }