docs: public static String getFiledType(FieldType type, boolean isList) {
          if ((type == FieldType.STRING || type == FieldType.BYTES) && !isList) {
              return "com.google.protobuf.ByteString";
          }
          
          // add null check
          String defineType = type.getJavaType();
          if (isList) {
              defineType = "List";
          }
          
          return defineType;
          
      }