Recordclass library provide record-like classes that do not by default
participate in cyclic garbage collection (CGC) mechanism, but support
only reference counting mechanism for garbage collection. The instances
of such classes havn't PyGC_Head prefix in the memory, which decrease
their size and have a little faster path for the instance allocation
and deallocation. This may make sense in cases where it is necessary to
limit the size of the objects as much as possible, provided that they
will never be part of references cycles in the application. For example,
when an object represents a record with fields with values of simple
types by convention (int, float, str, date/time/datetime, timedelta, etc.).