Cal Bera

@yihuang @dreamer-zq I've proposed an approach to use `CacheContext` and still handle nested reverts. Essentially, by implementing the cache contexts in the statedb journals, cache contexts can follow the snapshot/revert...

+1

[The PATH Variable Explained for Beginners](https://codingflashlight.com/the-path-variable-explained/) @garrettparris

Awesome, that would be great!

 We should send a `NewTxsEvent` on batch txs

current version is the logic used by geth’s light client txpool. now have to support pending and queued txs from geths core txpool

 Also adding support for the .Error check, I think we should do this (as Geth does) whenever accessing anything that could have caused an error (nonce, balance specifically)

Also we are now exposing the state plugin to be read from multiple threads, so do we need to lock there?

This PR should just introduce read-only changes, namely enabling RPC methods: `GetPoolNonce`, `SubscribeNewTxsEvent`

So I don’t think we need to merge this one. Implementing it via geth’s txpool provides more features and more testing, we just have to configure it correctly