CometCallbackHandler

Run when LLM starts.

Run when LLM generates a new token.

Run when LLM ends running.

Run when LLM errors.

Run when chain starts running.

Run when chain ends running.

Run when chain errors.

Run when tool starts running.

Run when tool ends running.

Run when tool errors.

Run when agent is ending.

Run when agent ends running.

Run on agent action.

Flush the tracker and setup the session.

Everything after this will be a new table.