IN = None
INOUT = None

FILE_IN = None
FILE_OUT = None
FILE_INOUT = None

COLLECTION_IN = None
COLLECTION_INOUT = None
COLLECTION_OUT = None

Type = 'type'  # parameter type
Direction = 'direction'  # parameter type
StdIOStream = 'stream'  # parameter stream
Prefix = 'prefix'  # parameter prefix
Depth = 'depth'  # collection recursive depth
