如何根据一些属性将对象分割成块?

public class InvestorMailing
{
    public string To { get; set; }

    public IEnumerable<string> Attachments { get; set; }

    public int AttachmentCount { get; set; }

    public long AttachmentSize { get; set; }
}
public class InvestorMailing
{
    public strin