SetOutput
Implements ISO's set_output/1: makes the stream identified by the argument (an alias or $stream(...) term) the current output stream, i.e. the one implicitly used by unary predicates like write/1-family and PutChar1 (see IOPrimitiveUtils.currentOutputChannel).
Throws
if the argument is unbound.
if it does not identify an open channel.
(stream_type) if it identifies an input channel instead.