public static FieldSpecification CreateFrom(FixedSizeFieldModel model)
        {
            var ret = CreateFrom(model as FieldModel);

            ret.Position = new FixedSizeSpecification()
            {
                Start = model.PositionStart,
                End   = model.PositionEnd
            };
            return(ret);
        }
 public FileBuilder AddField(FixedSizeFieldModel model)
 {
     this.Fields.Add(CreateFrom(model));
     return(this);
 }