ReadOnlyCollectionBaseT Class

public abstract class ReadOnlyCollectionBase<T> : IList<T>, 
	ICollection<T>, IEnumerable<T>, IEnumerable

Public MustInherit Class ReadOnlyCollectionBase(Of T)
	Implements IList(Of T), ICollection(Of T), 
	IEnumerable(Of T), IEnumerable

generic<typename T>
public ref class ReadOnlyCollectionBase abstract : IList<T>, 
	ICollection<T>, IEnumerable<T>, IEnumerable

[<AbstractClassAttribute>]
type ReadOnlyCollectionBase<'T> =  
    class
        interface IList<'T>
        interface ICollection<'T>
        interface IEnumerable<'T>
        interface IEnumerable
    end

var project = new Project(DataDir + "VbaProject.mpp");
var vbaProject = project.VbaProject;

Console.WriteLine("Total Modules Count: " + vbaProject.Modules.Count);
foreach (var module in vbaProject.Modules)
{
    Console.WriteLine("Module Name: " + module.Name);
    Console.WriteLine("Source Code: " + module.SourceCode);
    Console.WriteLine();
}

// the collection can be converted into a plain list
List<VbaModule> modules = vbaProject.Modules.ToList();
foreach (var unused in modules)
{
    // work with modules
}