Upon the addition of a Priority object to an Event (e.g., using Event::setPriority()), the SBML Level, SBML Version and XML namespace of the document override the values used when creating the Priority object via this constructor. This is necessary to ensure that an SBML document is a consistent structure. Nevertheless, the ability to supply the values at the time of creation of a Priority is an important aid to producing valid SBML. Knowledge of the intented SBML Level and Version determine whether it is valid to assign a particular value to an attribute, or whether it is valid to add a particular Priority object to an existing Event.
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