Added an implementation of attributes to GenEvent
Added an implementation of attributes to GenEvent to persistent classes. The changes constitute a new version 6 of the storage. Otherwise the content is equivalent to the version 5. So far the version 5 should be the default.
Tag @ewelina @jchapman @cgutscho @jkretz @hmildner @gpanizzo
@jchapman , will you have a look?
Some more notes:
- The v6 is in development phase.
- The v6 so far has more members than v5 -- to store the attributes.
- In the HepMC3 version there is a potential to save some space for the event size. One can drop the vertex weights, color flows and polarization members and save them as attributes only in case those exist.
Edited by Andrii Verbytskyi