@Contract(pure = true)
  public boolean packagePrefixExists(String packageQName) {
    for (final String prefix : myPackagePrefixIndex.getAllPackagePrefixes(null)) {
      if (StringUtil.startsWithConcatenation(prefix, packageQName, ".") || prefix.equals(packageQName)) {
        return true;
      }
    }

    return false;
  }
@Contract(pure = true)
  public boolean packagePrefixExists(String packageQName)