code: def update(cls, customer_id, **kwargs):
          
          return cls().requests.put('customer/{customer_id}'.format(**locals()),
                                    data=kwargs)
docs: Static method defined to update paystack customer data by id.
  
          Args:
              customer_id: paystack customer id.
              first_name: customer's first name(optional).
              last_name: customer's last name(optional).
              email: customer's email address(optional).
              phone:customer's phone number(optional).
  
          Returns:
              Json data from paystack API.