Dll not getting deployed even if it is in the .vsix file

So currently I am trying to reference the `Microsoft.Xaml.Behaviors.Wpf` dll from nuget. I can verify that the dll is inside the .vsix file, but if I try to call any method/class from within the package it will tell me that the assembly could not be found.

var assemblies = AppDomain.CurrentDomain.GetAssemblies();

var sorted = assemblies.Select(x =>
{

    try
    {
        return (x.FullName, x.Location);
    }
    catch
    {
        return (x.FullName, "");
    }


}).OrderBy(x => x.FullName).ToList();

If I debug the extension and inspect the `test` variable, I can see that it hasn't been loaded, even if I check the `AppDomain.CurrentDomain.BaseDirectory` directory and all its sub-folders I can't find the  `Microsoft.Xaml.Behaviors.Wpf` dll. Is this specific to this package and if so, what can I do about it?