Determines whether the relationship this part specifies is optional or not to traverse.
true, result tuples may have a null if this relationship can not be followed from some data objects.
false, all result tuples must contain this relationship.
Determines whether the relationship should be traversed recursively and whether the starting object should be included.
false: Traverse the relationship once.
'EXCLUDE_SELF': Traverse the relationship recursively, excluding the starting object.
'INCLUDE_SELF': Traverse the relationship recursively, including the starting object.
Specifies a relationship to traverse in the query.
Determines whether the related objects should be included in the result tuples.
true, related objects will be included.
false, the related objects are not included.
This does not impact whether the relationship is
optional to be traversed.