anchor.diff:  
   This can be changed with the <<Usage Help API,Help API>> for reordering sections. For example:
   
  -[source,java]
  +.Java
  +[source,java,role="primary"]
   ----
   import static picocli.CommandLine.Model.UsageMessageSpec.SECTION_KEY_AT_FILE_PARAMETER;
   import static picocli.CommandLine.Model.UsageMessageSpec.SECTION_KEY_COMMAND_LIST_HEADING;
  -import static picocli.CommandLine.Model.UsageMessageSpec.SECTION_KEY_OPTION_LIST_HEADING;
   
   @Command(name = "myapp", showAtFileInUsageHelp = true,
           mixinStandardHelpOptions = true, description = "Example command.")
  
positive.code: 
  Example command:
  
  [source,java]
  ----
  @Command(name = "myapp", showAtFileInUsageHelp = true,
          mixinStandardHelpOptions = true, description = "Example command.")
  class MyApp {
      @Parameters(description = "A file.") File file;
  }
  ----
  
  
negative.code: 
  CommandLine.usage(new DefaultValues(), System.out);
  ----
  
  .Kotlin
  [source,kotlin,role="secondary"]
  ----
  class DefaultValues {
      @Option(names = ["-f", "--file"], defaultValue = "config.xml",
          description = ["the file to use (default: \${DEFAULT-VALUE})"])
      lateinit var file: File
  }
  
  fun main(args: Array<String>) = CommandLine(DefaultValues()).usage(System.out)
  ----
  
  This produces the following usage help:
  ----
  Usage: <main class> [-f=<file>]
    -f, --file=<file>   the file to use (default: config.xml)
  ----
  
  