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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 execute(self, using=None):
 """ Populate the database using all the Entity classes previously added. :param using A Django database connection name :rtype: A list of the inserted PKs """

        if not using:
            using = self.getConnection()

        insertedEntities = {}
        for klass in self.orders:
            number = self.quantities[klass]
            if klass not in insertedEntities:
                insertedEntities[klass] = []
            for i in range(0,number):
                    insertedEntities[klass].append( self.entities[klass].execute(using, insertedEntities) )

        return insertedEntities