Add a callback to be executed when flag is visited before the flag value is set.

Add a processor to be executed before the flag value is set.

Add long name aliases for flag.

Set default value for flag.

Set description of flag.

Set environment variable to read for flag value.

Prevent flag from being displayed.

Don't display this group of flags.

Don't display the group name of the flags.

Create a new set.

Mark flag as being optional (default state).

Mark flag as being required.

Set the error handling mode for the Set.

Set the subtype of the flag (used for array and map types).

Set the mode for handling unknown flags.

Set short name for flag.

Array.

Boolean.

Float.

Increment.

Integer.

Map.

String.

Unset.