code: private float firstLineRealHeight() {
          float firstLineRealHeight = 0f;
          if (firstLine != null) {
              PdfChunk chunk = firstLine.getChunk(0);
              if (chunk != null) {
                  Image image = chunk.getImage();
                  if (image != null) {
                      firstLineRealHeight = firstLine.getChunk(0).getImage().getScaledHeight();
                  } else {
                      firstLineRealHeight = useAscender ? firstLine.getAscender() : leading;
                  }
              }
          }
          return firstLineRealHeight;
      }
docs: Calculates what the height of the first line should be so that the content will be
  flush with the top.  For text, this is the height of the ascender.  For an image,
  it is the actual height of the image.
  @return the real height of the first line