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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 has_joins(queryset):
 """Return True iff. a queryset includes joins. If this is the case, it is possible for the queryset to return duplicate results. """

    for join in six.itervalues(queryset.query.alias_map):
        if join.join_type:
            return True
    return False