[Zope] Cannot add an Edit tab to the management screen

[Bocquillon Philippe]

Hello,

I do not see an 'Edit' tab appearing in the management screens of my
(python) product with the following instruction:

    manage_options  = (
        {'label': 'Edit', 'action': 'manage_editChannelForm'},
        )+ObjectManager.ObjectManager.manage_options
+RoleManager.manage_options +Item.manage_options

Could you tell me what is wrong or what else in the code has to be checked
to make it working ?

Thanks in advance,

Philippe