code: public void registerPackagesFromAPI(MavenCoord apiCoords)
      {
          Iterable<String> packages = this.getPackagesInArtifact(apiCoords);
          for (String pkg : packages)
          {
              this.registerPackageInTypeInterestFactory(pkg);
          }
      }
docs: For given API artifact, finds the projects whose Java classes use artifact's classes,
  and links them in the graph.
  
  TODO:
  Because the graph doesn't contain data about all Java classes,
  this will likely need to use TypeInterestFactory -
  register all the classes (or just packages?) from the API jars.
  This is executed in a separate rule.