create a new changelog group with a version, date, and map of change type to changes.
create a new changelog group with a version, date, and map of change type to changes.
group version
group date
map of changeType of a sequence of changes
group date
map of changeType of a sequence of changes
group version
A group of changes, grouped by type, with a group version and date
group version
group date
map of changeType of a sequence of changes