View on Instance. Pass this enum to rpcs that returns an
Instance message to control which subsets of fields to get.
Values:
INSTANCE_VIEW_UNSPECIFIED (0):
INSTANCE_VIEW_UNSPECIFIED Not specified, equivalent to
BASIC.
INSTANCE_VIEW_BASIC (1):
BASIC server responses for a primary or read
instance include all the relevant instance
details, excluding the details of each node in
the instance. The default value.
INSTANCE_VIEW_FULL (2):
FULL response is equivalent to BASIC for
primary instance (for now). For read pool
instance, this includes details of each node in
the pool.