Modules
       groupinstance: process individual MIB instances easily.
       groupscalar: process scalars easily.
       groupscalar_group: process groups of scalars.
       groupwatcher: watch a specified variable and process
           it as an instance or scalar object

Detailed Description

       A group of handlers to implement individual leaf objects and instances
       (both scalar objects, and individual objects and instances within a
       table). These handlers will typically allow control to be passed down
       to a lower level, user-provided handler, but this is (usually)
       optional.

net-snmp leaf_handlers:0process individual leaf objects(3)