code: public ValidationMessageV3 fillFromImpl(ValidationMessage vm) {
      PojoUtils.copyProperties(this, vm, PojoUtils.FieldNaming.ORIGIN_HAS_UNDERSCORES);
      this.message_type = Log.LVLS[vm.log_level()]; // field name changed
      if (this.field_name != null) {
        if (this.field_name.startsWith("_"))
          this.field_name = this.field_name.substring(1);
        else
          Log.warn("Expected all ValidationMessage field_name values to have leading underscores; ignoring: " + field_name);
      }
      return this;
    }
docs: Version&Schema-specific filling from the implementation object