anchor.diff:  g.disconnectFrame(frame);
   g.removeFrame(frame);
   ----
  -
   ``disconnectFrame()`` removes all transforms that are connected to the given frame.
   Frames can only be removed, if they are not connected to the graph. I.e. if no
   edges are connected to the frame. An exception will be thrown, if the frame is
  
positive.code: #include <envire_core/items/Item.hpp>
  #include <octomap/AbstractOcTree.h>
  ----
  
  [source,c++]
  ----
  envire::core::Item<boost::shared_ptr<octomap::AbstractOcTree>>::Ptr octree;
  
negative.code: const FrameId frameB = "frame_b";
  Transform tf;
  g.addTransform(frameA, frameB, tf);
  ----
  Frames cannot be added twice. If a frame with the given name already exists,
  an exception will be thrown.
  