@Override
  public String toString() {
    StringBuilder buffer = new StringBuilder("content root:");
    for (Map.Entry<ExternalSystemSourceType, Collection<SourceRoot>> entry : data.entrySet()) {
      buffer.append(StringUtil.toLowerCase(entry.getKey().toString())).append("=").append(entry.getValue()).append("|");
    }
    if (!data.isEmpty()) {
      buffer.setLength(buffer.length() - 1);
    }
    return buffer.toString();
  }
@Override
  public String toString()