text: #ifndef CG1RAYTRACER_GROUPS_GROUP_HEADER
  #define CG1RAYTRACER_GROUPS_GROUP_HEADER
  
  #include <rt/primitive.h>
  #include <vector>
  
  namespace rt
  {
  
  /*
  A group is a container of multiple primitives.
  */
  class Group : public Primitive
  {
  public:
    typedef std::vector<Primitive*> Primitives;
    virtual void                    rebuildIndex()    = 0;
    virtual void                    add(Primitive* p) = 0;
  };
  }
  
  #endif
  