public MessageDescriptorBuilder <T> DoubleArray(int fieldNum, Func <T, IEnumerable <double> > valueGetter, Action <T, double> oneValueSetter, Func <T, bool> hasValueFunc = null, bool canReadPacked = true)
 {
     return(Add(FieldSetting <T> .CreateDoubleArray(fieldNum, valueGetter, oneValueSetter, hasValueFunc, canReadPacked)));
 }