# Functions
ContainsOpt checks whether option named `name` exist in the arguments.
GetArg returns the argument at `index`.
GetArgAll returns all parsed arguments.
GetOpt returns the option value named `name`.
GetOptAll returns all parsed options.
GetOptWithEnv returns the command line argument of the specified `key`.
Init does custom initialization.
ParseUsingDefaultAlgorithm parses arguments using default algorithm.