def METHOD_NAME(client, response):
    """Create a new customer mandate."""
    response.get(f"https://api.mollie.com/v2/customers/{CUSTOMER_ID}", "customer_single")
    response.post(f"https://api.mollie.com/v2/customers/{CUSTOMER_ID}/mandates", "customer_mandate_single")
    data = {
        "method": "directdebit",
        "consumerName": "John Doe",
        "consumerAccount": "NL55INGB0000000000",
        "consumerBic": "INGBNL2A",
        "signatureDate": "2018-05-07",
        "mandateReference": "YOUR-COMPANY-MD1380",
    }
    customer = client.customers.get(CUSTOMER_ID)
    mandate = customer.mandates.create(data)
    assert isinstance(mandate, Mandate)
    assert mandate.id == MANDATE_ID