C# partial properties

.filenesting.json

{
    "help": "https://go.microsoft.com/fwlink/?linkid=866610",
    "root": true,
    "dependentFileProviders": {
        "add": {
            "fileToFile": {
              "add": {
                "Client.Sets.cs": [
                  "Client.cs"
                ]
              }
            }
        }
    }
}

Client.cs

#nullable disable
using System.ComponentModel;

namespace TODO.Models;

public partial class Client : INotifyPropertyChanged
{
    public int Id { get; set; }
    public partial string FirstName { get; set; }
    public partial string LastName { get; set; }
}

Client.Sets.cs

#nullable disable
using System.ComponentModel;
using System.Runtime.CompilerServices;

namespace TODO.Models;
public partial class Client
{
    public partial string FirstName
    {
        get; set => SetField(ref field, value);
    }

    public partial string LastName
    {
        get; set => SetField(ref field, value);
    }
    public event PropertyChangedEventHandler PropertyChanged;

    protected void OnPropertyChanged(string propertyName)
        => PropertyChanged?.Invoke(this, new(propertyName));

    /// <summary>
    /// Sets the field to the specified value and raises the <see cref="PropertyChanged"/> event if the value has changed.
    /// </summary>
    /// <typeparam name="T">The type of the field.</typeparam>
    /// <param name="field">The field to set.</param>
    /// <param name="value">The value to set the field to.</param>
    /// <param name="propertyName">The name of the property. This is optional and will be automatically provided by the compiler.</param>
    /// <returns><c>true</c> if the field was changed; otherwise, <c>false</c>.</returns>
    protected bool SetField<T>(ref T field, T value, [CallerMemberName] string propertyName = "")
    {
        if (EqualityComparer<T>.Default.Equals(field, value)) return false;
        field = value;
        OnPropertyChanged(propertyName);
        return true;
    }
}