docs: public final int writeFieldName(String name)
      {
          if (_type == TYPE_OBJECT) {
              if (_currentName != null) { // just wrote a name...
                  return STATUS_EXPECT_VALUE;
              }
              _currentName = name;
              return (_index < 0) ? STATUS_OK_AS_IS : STATUS_OK_AFTER_COMMA;
          }
          return STATUS_EXPECT_VALUE;
      }