public Builder clearField(
                                  com.google.protobuf.Descriptors.FieldDescriptor field) {
            return (Builder) super.clearField(field);
        }
Protobuf type {@code com.alipay.sofa.rpc.protobuf.EchoRequest}
example/src/test/java/com/alipay/sofa/rpc/protobuf/EchoRequest.java