A /local variable/ of the constructor can be accessed from
within functions that are defined within the constructor.
This can be used to create /private fields/ of objects.
When objects of one constructor share a common method,
this method can be added to the /prototype/ of the constructor,
so that it does not have to be added to every object.
But can this be combined? Can we add a method to the
prototype of the constructor /and/ access /private/ fields
of the object from within this method?
(I see only the possibility to add at least a small
private method to /each and every object/, which then
might use helper method from the prototype.)