How to set default value of function string parameter to empty in Visual Studio 2013 UML class diagram designer?

Question

I want to setup function parameter setting in Visual Studio 2013 UML class diagram designer that result something like this code

public void Execute(string query = "")
    {
        ...
    }

Answer 1

Operation properties

Generated method looks like

public virtual void Execute(string query = "")
{
    throw new System.NotImplementedException();
}

Answer 2

What you are talking about is called an optional argument (in C#, at least). The original documentation is pretty good on this (https://msdn.microsoft.com/en-us/library/dd264739.aspx) but the gist of it is

public void Execute(int num, string optionalstr = "")

By doing this, num is required, and optionalstr is used if it is given, otherwise defaults to the right side of the equals, in this case: an empty string.