private boolean parseMappingPattern() {
    if (atToken(PyTokenTypes.LBRACE)) {
      SyntaxTreeBuilder.Marker mark = myBuilder.mark();
      nextToken();
      registerConsumedBracket(PyTokenTypes.LBRACE);
      parseCommaSeparatedPatterns(this::parseKeyValuePatternOrDoubleStarPattern);
      if (checkMatches(PyTokenTypes.RBRACE, PyParsingBundle.message("PARSE.expected.rbrace"))) {
        registerConsumedBracket(PyTokenTypes.RBRACE);
      }
      mark.done(PyElementTypes.MAPPING_PATTERN);
      return true;
    }
    return false;
  }
private boolean parseMappingPattern()