server/src/main/java/lossp/proto/RequestProto.java
public Builder clearUserId() {
        bitField0_ = (bitField0_ & ~0x00000002);
        userId_ = 0;
        onChanged();
        return this;
      }
/**
       * <code>required int32 userId = 2;</code>
       */
required int32 userId = 2.
required int32 userId = 2 .
public Builder clearUserId() {
        bitField0_ = (bitField0_ & ~0x00000002);
        userId_ = 0;
        onChanged();
        return this;
      }
public Builder clearUserId ( ) { bitField0_ = ( bitField0_ & ~ 0x00000002 ) ; userId_ = 0 ; onChanged ( ) ; return this ; }
<code>required int32 userId = 2;</code>
<code > required int32 userId = 2 ; < / code >