public Dictionary<string, object> ToDictionary()
{
  return this.GetType()
    .GetProperties(BindingFlags.Instance | BindingFlags.Public)
    .Where(prop => prop.GetCustomAttribute<JsonPropertyAttribute>() != null && prop.GetValue(this, null) != null && !string.IsNullOrEmpty(prop.GetValue(this, null).ToString()))
    .ToDictionary(prop => prop.GetCustomAttribute<JsonPropertyAttribute>().PropertyName, prop => prop.GetValue(this, null));
}