Functions in this page are used to specify the format of output results.
They are intended to provide the argument of functions such as
$output() and $predict().
Currently there are three types of output: out_file() indicates
that the result should be written into a file, out_memory() makes
the result to be returned as R objects, and out_nothing() means
the result is not needed and will not be returned.
out_file(path, ...)out_memory(...)
out_nothing(...)
Path to the output file.
Currently unused.
An object of class "Output" as required by
$output() and $predict().