@NotNull
  public static String getLineIndent(@NotNull Document document, int lineNumber) {
    final TextRange lineRange = TextRange.create(document.getLineStartOffset(lineNumber), document.getLineEndOffset(lineNumber));
    final String line = document.getText(lineRange);
    return getLineIndent(line);
  }
@NotNull
  public static String getLineIndent(@NotNull Document document, int lineNumber)