Added Entitlement enroll and unenroll logic to the Enrollment API

common/djangoapps/entitlements/models.py

@@ -24,3 +24,26 @@ class CourseEntitlement(TimeStampedModel):
         help_text='The current Course enrollment for this entitlement. If NULL the Learner has not enrolled.'
     )
     order_number = models.CharField(max_length=128, null=True)
+
+    @classmethod
+    def get_active_user_course_entitlements(cls, user, course_uuid):
+        """
+        Returns all the available sessions for a given course.
+        """
+
+        try:
+            entitlement = cls.objects.get(
+                user=user,
+                course_uuid=course_uuid,
+                expired_at=None,
+            )
+            return entitlement
+        except cls.DoesNotExist:
+            return None
+
+    @classmethod
+    def set_enrollment(cls, entitlement, enrollment):
+        """
+        Fulfills an entitlement by specifying a session.
+        """
+        cls.objects.filter(id=entitlement.id).update(enrollment_course_run=enrollment)