my $group = Munin::Master::Group->new($name, $parent);
Constructor. $name is the name of the group.
Sets attributes %attrs for the group. Valid attributes are:
An exception will be thrown if invalid attributes are provided.
(Full details here: <http://munin-monitoring.org/wiki/munin.conf#Groupleveldirectives>.)
Adds host $host to the group.
Propagates the attributes of $group to all hosts in the group. (This does not apply to hosts belonging to sub-groups.)
my @hosts = $group->get_all_hosts();
Returns the list of all hosts associated with this group, including those belonging to any sub-groups.