Aggregates all properties defined in a class to an
existing object, except for properties whose names start with
an underscore character (_) which are considered private to the
aggregated class.
See also
aggregate()
,
aggregate_methods()
,
aggregate_methods_by_list()
,
aggregate_methods_by_regexp()
,
aggregate_properties_by_list()
,
aggregate_properties_by_regexp()
,
aggregate_info()
,
deaggregate()