GeneratedMessageV3 and GeneratedMessage

[roshitjain]

Sir, this is a not a bug but explanation request.

Package com.google.protobuf has 2 classes GeneratedMessageV3 and GeneratedMessage.
Can you tell me what is the difference between the two?

Is it possible to force the generation of classes such that they extend from GeneratedMessage instead of GeneratedMessageV3?

protocArtifactId - com.google.protobuf:protoc:3.0.0-beta-1 & pluginArtifact - io.grpc:protoc-gen-grpc-java:0.9.1 used to generate classes which extend GeneratedMessage whereas

protocArtifactId - com.google.protobuf:protoc:3.0.0 & pluginArtifact - io.grpc:protoc-gen-grpc-java:1.1.1 generates classes which extend GeneratedMessageV3.

Is it possible to force the classes to extend from GeneratedMessage?

Thanks in advance.
I hope you get time to answer this tiny question.