←
input
ideal
•
library
•
channels
• output
interface
output
[contravariant
value
element
]
extends
closeable
,
syncable
not yet implemented readonly boolean
is available
not yet implemented readonly nonnegative
available
void
write
(
element
e
)
void
write all
(readonly
list
[
element
]
c
)
←
input
ideal
•
library
•
channels
• output