Each property key in this object is a "segment reference", which is how segments are identified in Big Segment data. This string is not identical to the segment key-- the SDK will add other information. The store implementation should not be concerned with the format of the string.
A true value means that the user is explicitly included in the segment. A false value means that the user is explicitly excluded from the segment-- and is not also explicitly included (that is, if both an include and an exclude existed in the data, the include would take precedence). If the user's status in a particular segment is undefined, there should be no key or value for that segment.
The return type of BigSegmentStore.getUserMembership, describing which Big Segments a specific user is included in or excluded from.
This object may be cached by the SDK, so it should not be modified after it is created. It is a snapshot of the segment membership state at one point in time.