anchor.diff:  = picocli - a mighty tiny Command Line Interface
   :author: Remko Popma
   :email: rpopma@apache.org
  -:revnumber: 0.9.5-SNAPSHOT
  -:revdate: 2017-05-04
  +:revnumber: 0.9.5
  +:revdate: 2017-05-09
   :toc: left
   :numbered:
   :toclevels: 2
  
positive.code: It is the responsibility of the application to check the field and show the usage help message:
  [source,java]
  ----
  Compress app = CommandLine.parse(new App(), args);
  if (app.helpRequested) {
     CommandLine.usage(new App(), System.err);
     return;
  
negative.code: === Best Practices for Command Line Interfaces
  
  When designing your command line application,
  the https://www.gnu.org/prep/standards/html_node/Command_002dLine-Interfaces.html#Command_002dLine-Interfaces[GNU recommendations] for command line interfaces and http://pubs.opengroup.org/onlinepubs/9699919799/basedefs/V1_chap12.html#tag_12_02[POSIX Utility Guidelines] may be useful.
  
  Generally, many applications use options for optional values and parameters for mandatory values.
  However, picocli lets you make options required if you want to, see <<Required Arguments>>.
  
  
  