code: public CustomCommandLine<?> getActiveCustomCommandLine(CommandLine commandLine) {
  		for (CustomCommandLine<?> cli : customCommandLines) {
  			if (cli.isActive(commandLine)) {
  				return cli;
  			}
  		}
  		throw new IllegalStateException("No command-line ran.");
  	}
docs: Gets the custom command-line for the arguments.
  @param commandLine The input to the command-line.
  @return custom command-line which is active (may only be one at a time)