Adds all nodes matching the regular expression to the specified class.
Refer to related perl documentation for the syntax of perl-style regular
expressions.
Adds all nodes matching the range expression to the specified class.
Any occurrence of a numerical range within brackets matches hostnames
having digits within that range. For instance the expression
rack[1-4]node[1-32] would match a host with the name
rack4node12.
| Note: A range is always enclosed in [ ] brackets. and
can be of the form a[-b][,x[-y]]... , where ab and xy