Explore ContractCallHandler / Tx using singledispatch here to call upwards to contract-type

[NotPeopling2day]

Overview

• [ ] Explore ContractCallHandler (in contracts/base.py Line 131) using singledispatch here to call upwards into self.contract_instance.contract_type and dynamically obtain the ABIs that match this method, reducing a lot of the logic in ContractInstance

Dependencies

Merge #509

[antazoey]

@NotPeopling2day Wondering if any of these checkboxes can be checked