Model Override - Plugin

namespace Nop.Plugin.ThemeHelper.AC.Models
{
    public partial class ACProductOverviewModel : ProductOverviewModel
    {
     ....
    }
}

namespace Nop.Plugin.ThemeHelper.AC.Models
{
    public partial class ACProductOverviewModel : ProductOverviewModel
    {
     ....
    }
}

namespace Nop.Plugin.ThemeHelper.AC.Models
{
    public partial class ACProductOverviewModel
    {
public ACProductOverviewModel()
{
  ProductOverviewModel= new ProductOverviewModel();
}
     public ProductOverviewModel ProductOverviewModel{get;set;}
........
    }
}

namespace Nop.Plugin.ThemeHelper.AC.Models
{
    public partial class ACProductOverviewModel
    {
       public ACProductOverviewModel()
       {
           ProductOverviewModel= new ProductOverviewModel();
       }
       
       public ProductOverviewModel ProductOverviewModel{get;set;}

       public string newProperty1 {get;set;}
       public string newProperty2 {get;set;}
    }
}

public partial MyModel
{
  public string field1{get;set}
  public string field2{get;set}
}


public partial MyModel
{
  public string field3{get;set}
  public string field4{get;set}
  public string field5{get;set}
  public string field6{get;set}
}