vb.net - Hiding function on nested class -

public class class1  private names list(of string) private _class2 new class2  public sub addname(byval name string)     names.add(name)     _class2.add() end sub  public readonly property addage(byval name string) class2             _class2.index = names.indexof(name)         return _class2     end end property  public sub clear()     names.clear()     _class2.clear() end sub  public class class2      private _age list(of integer)     protected friend index integer      public property age() integer                     return _age(index)         end         set(byval value integer)             _age(index) = value         end set     end property      public sub add()         _age.add(0)     end sub      public sub clear()         _age.clear()     end sub  end class end class 

how can hide ,sub clear , sub add on class2, they'll visible on class1, like;

public sub clear()     names.clear()     _class2.clear() '<<<<<<< end sub 

i want not visible on sub main(), below.

sub main()     dim person new class1      person.addage("kid").clear() '<<<<<<     person.addage("kid").add() '<<<<<<  end sub 

if put protected, class1 cannot access it. if put protected friend, sub main() can still access them. , time.

used -hans passant- comment.

"trust in .net follows assembly boundaries. if 2 classes in 1 assembly there 2 programmers know how find each other if there's problem. way want put these classes in separate class library project. lets use friend. , whomever writes main method doesn't have friendly."