code: public static void remove(Xml root, String group)
      {
          Check.notNull(root);
          Check.notNull(group);
  
          for (final Xml node : root.getChildren(NODE_COLLISION))
          {
              if (node.readString(ATT_GROUP).equals(group))
              {
                  root.removeChild(node);
              }
          }
      }
docs: Remove the group node.
  
  @param root The root node (must not be <code>null</code>).
  @param group The group name to remove (must not be <code>null</code>).
  @throws LionEngineException If invalid argument.