novice questions

[Samuel Lokshin]

Hi,

I am new to agent++, and agentGen, I have read mail archive and PDF documentation for Agent++, and look at the examples.
I would like to use this product.
I have several questions:

1. In the mail archive I found the reply on the question about message flow on a SET request, but could not found the reply for the question about GET, GET_NEXT , and BULK requests. Could you please provide the message flow for them.

2. In the documentation several virtual functioned are mentioned for objects in a MibTable: 
MibLeaf::clone and MibLeaf::max_key and it says how important is to override them. 
As I understand AgentGen takes care about clone function, but I could not find any example for max_key,
could you please provide short example, and when do I need to overwrite this function.

3. Is this code enough to update row in a table or I need to call get_rows_cloned() function?
( I am updating MIB using the values I am monitoring.)
mib->lock_mib();
start_synch();
row = find_index(...);
set_row(row,..); //using my new values.
end_synch()
mib->unlock_mib();

4. In the documentation it states that Agent++ "transparently provides SNMPv1/v2c/v3 functionality". My question is 
How agent knows what message structure it has to create (snmp message version field is for sure different)?

Thank you in advance.

Samuel Lokshin.