jsonrpc property
JSONRPC is always "2.0". An upstream that omits it has it filled in, so a client never has to cope with a response that is missing the one field telling it which protocol it is reading.
Please note: This property should have been non-nullable! Since the specification file does not include a default value (using the "default:" property), however, the generated source code must fall back to having a nullable type. Consider adding a "default:" property in the specification file to hide this note.
Implementation
String? jsonrpc;