code: def add_object(self,
                     name,
                     mesh,
                     transform=None):
          
  
          # if no transform passed, assume identity transform
          if transform is None:
              transform = np.eye(4)
          transform = np.asanyarray(transform, dtype=np.float32)
          if transform.shape != (4, 4):
              raise ValueError('transform must be (4,4)!')
  
          # create or recall from cache BVH
          bvh = self._get_BVH(mesh)
          # create the FCL transform from (4,4) matrix
          t = fcl.Transform(transform[:3, :3], transform[:3, 3])
          o = fcl.CollisionObject(bvh, t)
  
          # Add collision object to set
          if name in self._objs:
              self._manager.unregisterObject(self._objs[name])
          self._objs[name] = {'obj': o,
                              'geom': bvh}
          # store the name of the geometry
          self._names[id(bvh)] = name
  
          self._manager.registerObject(o)
          self._manager.update()
          return o
docs: Add an object to the collision manager.
  
          If an object with the given name is already in the manager,
          replace it.
  
          Parameters
          ----------
          name : str
            An identifier for the object
          mesh : Trimesh object
            The geometry of the collision object
          transform : (4,4) float
            Homogenous transform matrix for the object