src/main/java/de/digitalcollections/iiif/model/sharedcanvas/Resource.java
public Resource addRendering(OtherContent first, OtherContent... rest) {
    if (renderings == null) {
      this.renderings = new ArrayList<>();
    }
    List<OtherContent> renderingsToAdd = Lists.asList(first, rest);
    renderingsToAdd.forEach(this::verifyRendering);
    this.renderings.addAll(renderingsToAdd);
    return this;
  }
public Resource addRendering(OtherContent first, OtherContent... rest) {
    if (renderings == null) {
      this.renderings = new ArrayList<>();
    }
    List<OtherContent> renderingsToAdd = Lists.asList(first, rest);
    renderingsToAdd.forEach(this::verifyRendering);
    this.renderings.addAll(renderingsToAdd);
    return this;
  }
Add one or more renderings. All renderings must have both a profile and a format.

@param first first rendering
@param rest list of other renderings
@return current instance
@throws IllegalArgumentException if at least one rendering does not have both a profile and a format.