ArgOptions options = new ArgOptions();
options.addOption('s', "sentenceFile",
"a file where each line is a sentence", true,
"FILE[,FILE...]", "Required (at least one of)");
options.addOption('o', "outputFormat", "the .sspace format to use",
true, "{text|binary}", "Program Options");
// options.addOption('t', "threads", "the number of threads to use",
// true, "INT", "Program Options");
options.addOption('w', "overwrite", "specifies whether to " +
"overwrite the existing output", true, "BOOL",