NHibernate user type to trim char(n) columns

TrimmedString.cs

public class TrimmedString : IUserType
{
    public bool IsMutable 
    { 
        get { return false; } 
    }
    public Type ReturnedType 
    { 
        get { return typeof (string); } 
    }

    public SqlType[] SqlTypes
    {
        get { return new SqlType[1] { new SqlType(DbType.AnsiStringFixedLength) }; }
    }

    public object Assemble(object cached, object owner)
    {
        return this.DeepCopy(cached);
    }

    public object DeepCopy(object value)
    {
        if (value == null)
        {
            return (object) null;
        }
        else
        {
            return (object) string.Copy((string) value);
        }
    }

    public object Disassemble(object value)
    {
        return this.DeepCopy(value);
    }

    public bool Equals(object x, object y)
    {
        if (x == null)
        {
            return y == null;
        }
        else
        {
            return x.Equals(y);
        }
    }

    public int GetHashCode(object x)
    {
        return x.GetHashCode();
    }

    public object NullSafeGet(IDataReader rs, string[] names, object owner)
    {
        string str = (string) NHibernateUtil.String.NullSafeGet(rs, names[0]);
        return str != null ? (object) str.Trim() : (object) (string) null;
    }

    public void NullSafeSet(IDbCommand cmd, object value, int index)
    {
        if (value == null)
        {
            NHibernateUtil.String.NullSafeSet(cmd, (object) null, index);
        }
        else
        {
            value = (object) ((string) value).Trim();
            NHibernateUtil.String.NullSafeSet(cmd, value, index);
        }
    }

    public object Replace(object original, object target, object owner)
    {
        return original;
    }
}