Class Membership (1.12.1) 

Membership(value)

Whether the binding includes the principal.

    -  A principal is included directly if that principal is
       listed in the binding.
    -  A principal is included indirectly if that principal is
       in a Google group or Google Workspace domain that is
       listed in the binding.
MEMBERSHIP_NOT_INCLUDED (2):
    The binding does not include the principal.
MEMBERSHIP_UNKNOWN_INFO_DENIED (3):
    The sender of the request is not allowed to
    access the binding.
MEMBERSHIP_UNKNOWN_UNSUPPORTED (4):
    The principal is an unsupported type. Only
    Google Accounts and service accounts are
    supported.

Enums
Name Description
MEMBERSHIP_UNSPECIFIED Default value. This value is unused.
MEMBERSHIP_INCLUDED The binding includes the principal. The principal can be included directly or indirectly. For example: