code: public M selectPosition(T selectedEntity)
      {
          Checks.notNull(selectedEntity, "Channel");
          validateInput(selectedEntity);
  
          return selectPosition(orderList.indexOf(selectedEntity));
      }
docs: Selects a new current entity based on the index of
  the specified entity in the {@link #getCurrentOrder() current order}
  <br>This is a convenience function that uses {@link #selectPosition(int)} internally
  
  @param  selectedEntity
  The entity for the new position that will be in focus for all modification
  operations
  
  @return The current OrderAction sub-implementation instance
  
  @see    #selectPosition(int)
  @see    #getSelectedPosition()
  @see    #getSelectedEntity()