anchor.diff:  .Examples of valid abbreviations
   [options="header"]
   |===
  -|Option or Subcommand|Recognized Abbreviations
  -|`--veryLongCamelCase` | `--very`, `--vLCC`, `--vCase`
  -|`--super-long-option` | `--sup`, `--sLO`, `--s-l-o`, `--s-lon`, `--s-opt`, `--sOpt`
  -|`some-long-command` | `so`, `sLC`, `s-l-c`, `soLoCo`, `someCom`
  +|Option or Subcommand|Sample Recognized Abbreviations
  +|`--veryLongCamelCase` | `--very`, `--vLCC`, `--vCase` (...)
  +|`--super-long-option` | `--sup`, `--sLO`, `--s-l-o`, `--s-lon`, `--s-opt`, `--sOpt` (...)
  +|`some-long-command` | `so`, `sLC`, `s-l-c`, `soLoCo`, `someCom` (...)
   |===
   
   ==== Ambiguous Abbreviations
   When the user specifies input that can match multiple options or subcommands, the parser throws a `ParameterException`.
  -When applications use the `execute` method, a <<Invalid User Input,short error message>> and the usage help is displayed to the user.
  +When applications use the `execute` method, an error message and the usage help is <<Invalid User Input,displayed>> to the user.
   
   For example, given a command with subcommands `help` and `hello`, then ambiguous user input like `hel` will show this error message:
   
  
positive.code: When the unmatched value is similar to the known options, picocli throws an `UnmatchedArgumentException`
  rather than treating it as a positional parameter.
  
  As usual, `CommandLine.setUnmatchedArgumentsAllowed(true)` will accept unmatched input and
  display a WARN-level message on the console.
  
  
  Arguments that are not considered similar to the known options are interpreted as positional parameters:
  
negative.code: Prior to 4.0, the default was to "toggle" boolean flags to the opposite of their _current_ value:
  if the previous value was `true` it is set to `false`, and when the value was `false` it is set to `true`.
  
  Applications can call `CommandLine::setToggleBooleanFlags` with `true` to enable toggling.
  Note that when toggling is enabled, specifying a flag option twice on the command line will have no effect because they cancel each other out.
  
  
  === POSIX Clustered Short Options
  By default, the picocli parser allows POSIX clustered short options, so short options like `-x -v -f SomeFile` can be clustered together like `-xvfSomeFile`.
  From picocli 3.0, applications can call `CommandLine::setPosixClusteredShortOptionsAllowed` with `false` to enforce that options must be separated with whitespace on the command line.
  (This also means that option parameters must be separated from the option name by whitespace or the `=` <<Option-Parameter Separators,separator>> character, so `-D key=value` and `-D=key=value` will be recognized but `-Dkey=value` will not.)
  
  === Lenient Mode
  From picocli 3.2, the parser can be configured to continue parsing invalid input to the end.
  When `collectErrors` is set to `true`, and a problem occurs during parsing, an `Exception` is added to the list returned by `ParseResult::errors` and parsing continues. The default behaviour (when `collectErrors` is `false`) is to abort parsing by throwing the `Exception`.
  
  This is useful when generating completion candidates on partial input, and is also useful when using picocli in
  languages like Clojure where idiomatic error handling does not involve throwing and catching exceptions.
  