![show/hide quicksearch [+]](../images/find.png)
Hash with completion search feature. See OptionParser::Completion.
Completion for hash key.
 
               # File optparse.rb, line 932
def match(key)
  *values = fetch(key) {
    raise AmbiguousArgument, catch(:ambiguous) {return complete(key)}
  }
  return key, *values
end