Values:
UNKNOWN_KIND (0):
Unrecognized transform type.
PAR_DO_KIND (1):
ParDo transform.
GROUP_BY_KEY_KIND (2):
Group By Key transform.
FLATTEN_KIND (3):
Flatten transform.
READ_KIND (4):
Read transform.
WRITE_KIND (5):
Write transform.
CONSTANT_KIND (6):
Constructs from a constant value, such as
with Create.of.
SINGLETON_KIND (7):
Creates a Singleton view of a collection.
SHUFFLE_KIND (8):
Opening or closing a shuffle session, often
as part of a GroupByKey.
