private static void parseMysqlCharEqExpression(PsiBuilder builder) {
    final PsiBuilder.Marker marker = builder.mark();
    builder.advanceLexer();
    checkMatches(builder, RegExpTT.CHARACTER, RegExpBundle.message("parse.error.character.expected"));
    checkMatches(builder, RegExpTT.MYSQL_CHAR_EQ_END, RegExpBundle.message("parse.error.unclosed.mysql.character.equivalence.class"));
    marker.done(RegExpElementTypes.MYSQL_CHAR_EQ_EXPRESSION);
  }
private static void parseMysqlCharEqExpression(PsiBuilder builder)