https://github.com/ethereum/wiki/wiki/RLP
Because none of this makes sense without it.
https://github.com/PointyCastle/pointycastle/blob/master/lib/src/utils.dart
utils.dart file was used for converting between BigInt and Uint8List
https://github.com/ethereumjs/rlp
Used as a reference point for code and tests
https://github.com/ethereum/tests
For the official RLP tests