Fixed - `EntitySet.ids` iterating on its elements instead of copying the internal identifiers. - RDF/XML parser failing on unknown datatypes ([187](https://github.com/althonos/pronto/issues/187)). Changed - Disable typechecking when collecting entities in `to_set` methods.
2.5.0
Changed - Bumped `fastobo` dependecy to `v0.12.1` Removed - Support for Python 3.6.
2.4.7
Fixed - Serialization of `is_class_level` properties with `fastobo`-based serializers ([178](https://github.com/althonos/pronto/issues/178)). - Parsing of `SynonymTypeProperty` elements in RDF/XML without a label attribute ([176](https://github.com/althonos/pronto/issues/176)).
2.4.6
Added - Setters for the `holds_over_chain` and `equivalent_to_chain` properties of `Relationship` objects. Fixed - Serialization of `holds_over_chain` properties with `fastobo`-based serializers ([175](https://github.com/althonos/pronto/issues/175)).
2.4.5
Fixed - Serialization of *metadata tag* relationships by `fastobo` ([164](https://github.com/althonos/pronto/issues/164)).
2.4.4
Added - `OwlFunctionalSerializer` to dump an `Ontology` to OWL Functional-style syntax. Changed - Bumped `fastobo` dependency to `v0.11.1`. - Make `FastoboParser` raise a `SyntaxWarning` when encoutering creation dates that are not `datetime.datetime`.