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Solve the following problem using Python, implementing the functions described below, one line at a time
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Description:
 def get_group(group):
 """Return the group :param group: The group name/id :returns: Group """

    portal_groups = get_tool("portal_groups")
    if isinstance(group, basestring):
        group = portal_groups.getGroupById(group)
    elif isinstance(group, GroupData):
        group = group
    return group