finalize() {
    //console.log(JSON.stringify(this.lines, null, 2));

    this.determineLineHeights();
    this.determineLabelSize();
    const tmpLines = this.removeEmptyBlocks();

    // Return a simple hash object for further processing.
    return {
      width: this.width,
      height: this.height,
      lines: tmpLines,
    };
  }
Set the sizes for all lines and the whole thing.
@returns {{width: (number|*), height: (number|*), lines: Array}}