The LocationArgument class is used to specify a location in the command sender's current world. This allows the user to enter three numbers as coordinates, or use relative coordinates (i.e. the ~ and ^ operators)

The LocationArgument constructor requires a LocationType, which specifies the type of location that is accepted by the command.

Integer block coordinates. The suggested location is the coordinates of block you are looking at when you type the command.

Exact coordinates. The suggested location is the exact coordinates of where your cursor is pointing at when you type the command.

By default, the LocationArgument will use PRECISE_POSITION.

LinkedHashMap<String, Argument> arguments = new LinkedHashMap<>();

//We want to target blocks in particular, so use BLOCK_POSITION
arguments.put("block", new LocationArgument(LocationType.BLOCK_POSITION));

CommandAPI.getInstance().register("break", arguments, (sender, args) -> {
    ((Location) args[0]).getBlock().setType(Material.AIR);
});