def _build_payment_code_notebook_60(sender, reference_number,
    payment_identification, quantity):
    """ Payment code is calculated concatenating 6 values:

        - A constant that represents this payment mode: '90521'
        - A 6 digit sender code: '123456'
        - A 12 digit reference number: '123456789012'
        - A 10 digit payment identification number: '1234567890'
        - A 8 digit value representing the number of euro cents to
            be payed: '0000001000'
        - A constant value: '0'
    """
    return (
        '90521{sender:0>6}{reference_number:0>12}{payment_identification:0>10}{quantity:0>8}0'
        .format(sender=sender, reference_number=reference_number,
        payment_identification=payment_identification, quantity=quantity))
