# All-approach: clusters contains less or equal event ids compared to all events that have a relation to a instance of the specified object type
# Cause: One event can have relations to multiple instances (shopping multiple products) and they can occur in different clusters, hence the event is assigned to no cluster
# Existence-approach: clusters contains more or equal event ids compared to all events that have a relation to a instance of the specified object type.
# Cause: One event can have relations to multiple instances (shopping multiple products) and they can occur in different clusters, hence the event is assigned to multiple clusters
clusters.reset_index(inplace=True)
ocel_clusters = []
groups = clusters.groupby('cluster')['ocel:eid'].apply(list).reset_index(name='event_list').set_index('cluster')