<SYSTEM_TASK:>
Solve the following problem using Python, implementing the functions described below, one line at a time
<END_TASK>
<USER_TASK:>
Description:
 def is_object(brain_or_object):
 """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 """

    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