Check that $mode in InputArgument::__construct() is not below 1 to actually look if any of the flags are set.
Check that $mode in InputOption::__construct() is not below 1 to actually look if any of the flags are set.
Check for the correct parameter type, as in InputOption (integer).
InputArgumentTest: Added test for negative integer $mode parameter input in constructor.
InputOptionTest: Added test for negative integer $mode parameter input in constructor.