'Gets provider by provider_id string if enabled, else None.'

@classmethod
def get(cls, provider_id):

    if ('-' not in provider_id):
        raise ValueError('Invalid    provider_id.    Expect    something    like    oa2-google')
    try:
        return next((provider for provider in cls._enabled_providers() if (provider.provider_id == provider_id)))
    except StopIteration:
        return None
