private int getBlankLineOffset(int blankLinesNumber, int startOffset) {
      int startLine = myDocument.getLineNumber(startOffset);
      if (startLine <= 0) {
        return 0;
      }
      CharSequence text = myDocument.getCharsSequence();
      for (int i = myDocument.getLineStartOffset(startLine - 1) - 1; i >= 0; i = CharArrayUtil.lastIndexOf(text, "\n", i - 1)) {
        if (--blankLinesNumber <= 0) {
          return i + 1;
        }
      }
      return 0;
    }
private int getBlankLineOffset(int blankLinesNumber, int startOffset)