code: protected Val nextSimpleValue() throws IOException {
        switch (currentValue.getKey()) {
           case NULL:
           case STRING:
           case BOOLEAN:
           case NUMBER:
              Val object = currentValue.v2;
              consume();
              return object;
           default:
              throw new IOException("Expecting VALUE, but found " + jsonTokenToStructuredElement(null));
        }
     }
docs: Next simple value val.
  
  @return the val
  @throws IOException the io exception