code: def is_object(brain_or_object):
      
      if is_portal(brain_or_object):
          return True
      if is_at_content(brain_or_object):
          return True
      if is_dexterity_content(brain_or_object):
          return True
      if is_brain(brain_or_object):
          return True
      return False
docs: Check if the passed in object is a supported portal content object
  
      :param brain_or_object: A single catalog brain or content object
      :type brain_or_object: Portal Object
      :returns: True if the passed in object is a valid portal content