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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 _register_aggregate(agg, con):
 """Register a Python class that performs aggregation in SQLite. Parameters agg : type con : sqlalchemy.Connection """

    nargs = number_of_arguments(agg.step) - 1  # because self
    con.connection.connection.create_aggregate(agg.__name__, nargs, agg)