| Class | BaseProtocolTests | Undocumented |
| Class | ProtocolTests | Undocumented |
| Class | ReceivableBytesIO | BytesIO with socket-like recv semantics for testing. |
| Class | ReceivableProtocolTests | Undocumented |
| Class | CapabilitiesTestCase | Undocumented |
| Class | BufferedPktLineWriterTests | Undocumented |
| Class | PktLineParserTests | Undocumented |