Fixed circular imports

owlapy/abstracts/abstract_owl_ontology.py

@@ -1,15 +1,17 @@
 from abc import ABCMeta, abstractmethod
-from typing import Final, Iterable, Union, Optional
+from typing import Final, Iterable, Union, Optional, TypeVar
 
 from owlapy.class_expression import OWLClass
 from owlapy.iri import IRI
 from owlapy.owl_axiom import OWLEquivalentClassesAxiom, OWLClassAxiom, OWLDataPropertyDomainAxiom, \
     OWLDataPropertyRangeAxiom, OWLObjectPropertyDomainAxiom, OWLObjectPropertyRangeAxiom, OWLAxiom
 from owlapy.owl_individual import OWLNamedIndividual
 from owlapy.owl_object import OWLObject
-from owlapy.owl_ontology import _M, OWLOntologyID
 from owlapy.owl_property import OWLDataProperty, OWLObjectProperty
 
+_M = TypeVar('_M', bound='OWLOntologyManager')  # noqa: F821
+_OI = TypeVar('_OI', bound='OWLOntologyID')  # noqa: F821
+
 
 class OWLOntology(OWLObject, metaclass=ABCMeta):
     """Represents an OWL 2 Ontology  in the OWL 2 specification.
@@ -136,7 +138,7 @@ def get_owl_ontology_manager(self) -> _M:
         pass
 
     @abstractmethod
-    def get_ontology_id(self) -> OWLOntologyID:
+    def get_ontology_id(self) -> _OI:
         """Gets the OWLOntologyID belonging to this object.
 
         Returns: