Should code and AVId be unique?

[pedroripper]

Currently, one can create two elements from the same collection or not, with the same codes and AVIds

using PSRClassesInterface; PSRI = PSRClassesInterface

temp_path = joinpath(tempdir())
data = PSRI.create_study(PSRI.OpenInterface(); data_path = temp_path)

PSRI.create_element!(data, "PSRBus",   "AVId" => "1", "code" => Int32(1))
PSRI.create_element!(data, "PSRBus",   "AVId" => "1", "code" => Int32(1))
PSRI.create_element!(data, "PSRSerie", "AVId" => "1", "code" => Int32(1))

The unique identifier that is used in PSRI is reference_id, which the user cannot set by themself. PSRI "calculates" the reference_id for the new element during creation.

Should we set code and AVId to be unique? Either for elements from the same collection or the whole study.