Ensure APIs are complete by validating that all necessary cases are handled, all required arguments are properly validated, and response structures are consistent across similar operations. Key areas to check: 1. **Switch statement completeness**: When adding new enum values or operation types, ensure all switch statements that handle them include the new cases 2. **Argument validation coverage**: Test all invalid argument combinations, not just the happy path scenarios 3. **Response structure consistency**: Maintain consistent field presence across similar API responses (e.g., if one response has top-level error codes, related responses should too) 4. **Parameter naming consistency**: Follow established naming conventions from KIPs and existing APIs Example from the discussions: ```java // Incomplete - missing new RPC cases case UPDATE_VOTER: handledSuccessfully = handleUpdateVoterResponse(response, currentTimeMs); break; // Need to add: case ADD_RAFT_VOTER: handledSuccessfully = handleAddVoterResponse(response, currentTimeMs); break; case REMOVE_RAFT_VOTER: handledSuccessfully = handleRemoveVoterResponse(response, currentTimeMs); break; ``` This prevents runtime failures from unhandled cases and ensures consistent developer experience across the API surface.