code: @Nullable
    public static IJson readJson (@Nonnull @WillClose final Reader aReader,
                                  @Nullable final IJsonParserCustomizeCallback aCustomizeCallback,
                                  @Nullable final IJsonParseExceptionCallback aCustomExceptionCallback)
    {
      final CollectingJsonParserHandler aHandler = new CollectingJsonParserHandler ();
      if (parseJson (aReader, aHandler, aCustomizeCallback, aCustomExceptionCallback).isFailure ())
        return null;
      return aHandler.getJson ();
    }
docs: Main reading of the JSON
  
  @param aReader
  The reader to read from. Should be buffered. May not be
  <code>null</code>.
  @param aCustomizeCallback
  An optional {@link JsonParser} customization callback. May be
  <code>null</code>.
  @param aCustomExceptionCallback
  A custom handler for unrecoverable errors. May be <code>null</code>.
  @return <code>null</code> if parsing failed with an unrecoverable error
  (and no throwing exception handler is used), or <code>null</code>
  if a recoverable error occurred or non-<code>null</code> if parsing
  succeeded.
  @since 9.1.8