'Constructor, which passes all config directives to the config class
via kwargs. For example:
paypal = PayPalInterface(API_USERNAME=\'somevalue\')
Optionally, you may pass a \'config\' kwarg to provide your own
PayPalConfig object.'

def __init__(self, config=None, **kwargs):

    if config:
        self.config = config
    else:
        self.config = PayPalConfig(**kwargs)
