anchor.diff:  Similarly for <<Maps>>:
   [source,java]
   ----
  -@Option(names = "-fix", split = "\\|", type = {Integer.class, String.class})
  -Map<Integer,String> message;
  +@Option(names = "-fix", split = "\\|")
  +Map<Integer, String> message;
   ----
   With the above option, command line arguments like the following are interpreted as a set of key-value pairs instead of a single string:
   ----
   -fix 8=FIX.4.4|9=69|35=A|49=MBT|56=TargetCompID|34=9|52=20130625-04:05:32.682|98=0|108=30|10=052
   ----
  -
  -=== Multiple Occurrences
  -Users may also specify the same option multiple times. For example:
  -----
  --option 111 -option 222 -option 333
  -----
  -Each value is appended to the array or collection.
   
   
   == Required Arguments
  
positive.code: However, picocli lets you make options required if you want to, see <<Required Arguments>>.
  
  == Tracing
  From version 1.0.0, picocli supports parser tracing to facilitate troubleshooting.
  
  System property `picocli.trace` controls the trace level. Supported levels are `OFF`, `WARN`, `INFO`, and `DEBUG`. The default trace level is `WARN`.
  
  
negative.code: import java.io.File;
  
  class Convert {
      @Option(names = "-patterns", description = "the regex patterns to use");
      Pattern[] patterns;
  
      @Parameters(description = "the files to convert")
      List<File> files;
  }
  ----
  
  [source,java]
  ----
  String[] args = { "-patterns", "a*b", "-patterns", "[a-e][i-u]", "file1.txt", "file2.txt" };
  Convert convert = CommandLine.populateCommand(new Convert(), args);
  
  // convert.patterns now has two Pattern objects
  