fn flatten_contract_inheritance(
contract: ContractIR,
contract_map: &HashMap<String, ContractIR>,
) -> Result<(ContractIR, Vec<String>), SolidityError>fn flatten_contract_inheritance(
contract: ContractIR,
contract_map: &HashMap<String, ContractIR>,
) -> Result<(ContractIR, Vec<String>), SolidityError>