Partial Methods - Multiple implementing declarations alternate solution?

Question

I am currently trying to understand the purpose of partial methods as, the way in which i was hoping to use them was like an event.

Example.cs

public partial class Example 
{
    partial void LoadData();
    public void Example() 
    {
        LoadData();
    }

    public override void ToString() => (StringA + StringB);
}

Example.Hello.cs

public partial class Example
{
    public string StringA;
    partial void LoadData() 
    {
        StringA = "HELLO";
    }
}

Example.World.cs

public partial class Example
{
    public string StringB;
    partial void LoadData() 
    {
        StringB = "WORLD";
    }
}

public void Main 
{
    public void Main () 
    {
        Example ex = new Example();
        Console.Write(ex.ToString());
    }
}

Using the example pysudeo code above, I expect the Console to say "HELLOWORLD". This is how I originally thought partial methods should work, I believe I understand why it doesn't work this way, but I was hoping someone could help me come up with an alternative way of accomplishing this.

Essentially I only want to call one method and have that one method be able to lead all the data that I need for my Example.cs object.

TO BE CLEAR, i get that the application won't know how to order the function calls. but I honestly do not care for the order in my example. It could say "WORLDHELLO" for all i care.