method Deno.Command.prototype.outputSync
Command.prototype.outputSync(): CommandOutput
Synchronously executes the [`Deno.Command`](../././~/Deno.Command), waiting for it to
finish and collecting all of its output.
Will throw an error if `stdin: "piped"` is set.
If options `stdout` or `stderr` are not set to `"piped"`, accessing the
corresponding field on [`Deno.CommandOutput`](../././~/Deno.CommandOutput) will throw a `TypeError`.