add plone.api.content.update

i would like to see an update method, that really acts like updating (eg changing) using the mechanism used during a browser session.

inspiration:
i do have a package where i registered a custom method on the ObjectModifiedEvent.
during tests i create a structure of folders and pages using
plone.api.content.create(container, type, title, a_costum_field_from_my_behavior)
the method gets triggered -> container modified. so far, so good.

now i want to change the value of a_costum_field_from_my_behavior.
try 1:
self.portal.my-content-object.a_costum_field_from_my_behavior = new_value
-> no event triggered, not even after transaction.commit()

try 2:
z3c.form; get the field; update the value
-> no event triggered

try 3:
test browser; not what i wanted, as its not browser test, just a simple functional test. but itried at least -> no event triggered

thanks to @jensens i did it via zope.event.notify.
having to know was really hard work to get there and cost me several hours... i wouldn't even know how to search that (searching without knowing what to search is always hard)

thats why i would love to see an update method
plone.api.content.update(object, fields={field:value, field:value, ...})
which does the complete set of mechanisms done by plone in normal usage.