public static @NotNull String buildRegexp(@NotNull String pattern, int exactPrefixLen, boolean allowToUpper, boolean allowToLower) {
    return buildRegexp(pattern, exactPrefixLen, allowToUpper, allowToLower, false, false);
  }
public static @NotNull String buildRegexp(@NotNull String pattern, int exactPrefixLen, boolean allowToUpper, boolean allowToLower)