code: @Override
    public PackageDescriptor add(String pm, String groupId, String artifactId, String version) {
      PackageCoordinate pkg = PackageCoordinate.newBuilder()
          .withFormat(pm)
          .withNamespace(groupId)
          .withName(artifactId)
          .withVersion(version)
          .build();
      return add(Collections.singletonList(pkg));
    }
docs: /*
  (non-Javadoc)
  @see net.ossindex.common.IPackageRequest#add(java.lang.String, java.lang.String, java.lang.String, java.lang.String)