The spec for this action:
https://www.adobe.com/content/dam/acom/en/devnet/pdf/pdfs/PDF32000_2008.pdf#G11.2111850
An example of a form using this action:
https://www2.illinois.gov/rev/forms/reg/Documents/reg-1-mr.pdf
this.container.className = "lineAnnotation";
    
    
    
    const data = this.data;
    const width = data.rect[2] - data.rect[0];
    const height = data.rect[3] - data.rect[1];
    const svg = this.svgFactory.create(width, height);
    
    
    const line = this.svgFactory.createElement("svg:line");
    line.setAttribute("x1", data.rect[2] - data.lineCoordinates[0]);
    line.setAttribute("y1", data.rect[3] - data.lineCoordinates[1]);
    line.setAttribute("x2", data.rect[2] - data.lineCoordinates[2]);
    line.setAttribute("y2", data.rect[3] - data.lineCoordinates[3]);
    
    
    line.setAttribute("stroke-width", data.borderStyle.width || 1);
    line.setAttribute("stroke", "transparent");
    svg.appendChild(line);
    this.container.append(svg);
    
    
    this._createPopup(line, data);
    return this.container;
  }
}
class SquareAnnotationElement extends AnnotationElement {