Here is a picture of my Solution Explorer pane:

I've built the solution. Why do some of the class items not have the "VB" icon?
For example, here is the code for one of the classes that do not have the "VB" icon.
Code:
Public Class ToolStripCheckBox
'https://social.msdn.microsoft.com/Forums/vstudio/en-US/78ef28fa-c648-4187-8fb4-1bc5ae234b8b/toolstrip-checkbox?forum=vbgeneral
Inherits ToolStripControlHost
Public Sub New()
MyBase.New(New CheckBox)
End Sub
Private ReadOnly Property CheckBoxControl() As CheckBox
Get
Return CType(Control, CheckBox)
End Get
End Property
'Expose the CheckBoxControl's Checked Property
Public Property Checked() As Boolean
Get
Return CheckBoxControl.Checked
End Get
Set(ByVal value As Boolean)
CheckBoxControl.Checked = value
End Set
End Property
End Class