def __init__(self, *, credentials: credentials.Credentials=None, transport: Union[(str, JobServiceTransport)]=None, client_options: ClientOptions=None) -> None:
    'Instantiate the job service client.\n\n        Args:\n            credentials (Optional[google.auth.credentials.Credentials]): The\n                authorization credentials to attach to requests. These\n                credentials identify the application to the service; if none\n                are specified, the client will attempt to ascertain the\n                credentials from the environment.\n            transport (Union[str, ~.JobServiceTransport]): The\n                transport to use. If set to None, a transport is chosen\n                automatically.\n            client_options (ClientOptions): Custom options for the client. It\n                won\'t take effect if a ``transport`` instance is provided.\n                (1) The ``api_endpoint`` property can be used to override the\n                default endpoint provided by the client. GOOGLE_API_USE_MTLS\n                environment variable can also be used to override the endpoint:\n                "always" (always use the default mTLS endpoint), "never" (always\n                use the default regular endpoint, this is the default value for\n                the environment variable) and "auto" (auto switch to the default\n                mTLS endpoint if client SSL credentials is present). However,\n                the ``api_endpoint`` property takes precedence if provided.\n                (2) The ``client_cert_source`` property is used to provide client\n                SSL credentials for mutual TLS transport. If not provided, the\n                default SSL credentials will be used if present.\n\n        Raises:\n            google.auth.exceptions.MutualTLSChannelError: If mutual TLS transport\n                creation failed for any reason.\n        '
    if isinstance(client_options, dict):
        client_options = ClientOptions.from_dict(client_options)
    if (client_options is None):
        client_options = ClientOptions.ClientOptions()
    if (client_options.api_endpoint is None):
        use_mtls_env = os.getenv('GOOGLE_API_USE_MTLS', 'never')
        if (use_mtls_env == 'never'):
            client_options.api_endpoint = self.DEFAULT_ENDPOINT
        elif (use_mtls_env == 'always'):
            client_options.api_endpoint = self.DEFAULT_MTLS_ENDPOINT
        elif (use_mtls_env == 'auto'):
            has_client_cert_source = ((client_options.client_cert_source is not None) or mtls.has_default_client_cert_source())
            client_options.api_endpoint = (self.DEFAULT_MTLS_ENDPOINT if has_client_cert_source else self.DEFAULT_ENDPOINT)
        else:
            raise MutualTLSChannelError('Unsupported GOOGLE_API_USE_MTLS value. Accepted values: never, auto, always')
    if isinstance(transport, JobServiceTransport):
        if (credentials or client_options.credentials_file):
            raise ValueError('When providing a transport instance, provide its credentials directly.')
        if client_options.scopes:
            raise ValueError('When providing a transport instance, provide its scopes directly.')
        self._transport = transport
    else:
        Transport = type(self).get_transport_class(transport)
        self._transport = Transport(credentials=credentials, credentials_file=client_options.credentials_file, host=client_options.api_endpoint, scopes=client_options.scopes, api_mtls_endpoint=client_options.api_endpoint, client_cert_source=client_options.client_cert_source, quota_project_id=client_options.quota_project_id)
Instantiate the job service client.

Args:
    credentials (Optional[google.auth.credentials.Credentials]): The
        authorization credentials to attach to requests. These
        credentials identify the application to the service; if none
        are specified, the client will attempt to ascertain the
        credentials from the environment.
    transport (Union[str, ~.JobServiceTransport]): The
        transport to use. If set to None, a transport is chosen
        automatically.
    client_options (ClientOptions): Custom options for the client. It
        won't take effect if a ``transport`` instance is provided.
        (1) The ``api_endpoint`` property can be used to override the
        default endpoint provided by the client. GOOGLE_API_USE_MTLS
        environment variable can also be used to override the endpoint:
        "always" (always use the default mTLS endpoint), "never" (always
        use the default regular endpoint, this is the default value for
        the environment variable) and "auto" (auto switch to the default
        mTLS endpoint if client SSL credentials is present). However,
        the ``api_endpoint`` property takes precedence if provided.
        (2) The ``client_cert_source`` property is used to provide client
        SSL credentials for mutual TLS transport. If not provided, the
        default SSL credentials will be used if present.

Raises:
    google.auth.exceptions.MutualTLSChannelError: If mutual TLS transport
        creation failed for any reason.
def __init__(self, *, credentials: credentials.Credentials=None, transport: Union[(str, JobServiceTransport)]=None, client_options: ClientOptions=None) -> None:
    'Instantiate the job service client.\n\n        Args:\n            credentials (Optional[google.auth.credentials.Credentials]): The\n                authorization credentials to attach to requests. These\n                credentials identify the application to the service; if none\n                are specified, the client will attempt to ascertain the\n                credentials from the environment.\n            transport (Union[str, ~.JobServiceTransport]): The\n                transport to use. If set to None, a transport is chosen\n                automatically.\n            client_options (ClientOptions): Custom options for the client. It\n                won\'t take effect if a ``transport`` instance is provided.\n                (1) The ``api_endpoint`` property can be used to override the\n                default endpoint provided by the client. GOOGLE_API_USE_MTLS\n                environment variable can also be used to override the endpoint:\n                "always" (always use the default mTLS endpoint), "never" (always\n                use the default regular endpoint, this is the default value for\n                the environment variable) and "auto" (auto switch to the default\n                mTLS endpoint if client SSL credentials is present). However,\n                the ``api_endpoint`` property takes precedence if provided.\n                (2) The ``client_cert_source`` property is used to provide client\n                SSL credentials for mutual TLS transport. If not provided, the\n                default SSL credentials will be used if present.\n\n        Raises:\n            google.auth.exceptions.MutualTLSChannelError: If mutual TLS transport\n                creation failed for any reason.\n        '
    if isinstance(client_options, dict):
        client_options = ClientOptions.from_dict(client_options)
    if (client_options is None):
        client_options = ClientOptions.ClientOptions()
    if (client_options.api_endpoint is None):
        use_mtls_env = os.getenv('GOOGLE_API_USE_MTLS', 'never')
        if (use_mtls_env == 'never'):
            client_options.api_endpoint = self.DEFAULT_ENDPOINT
        elif (use_mtls_env == 'always'):
            client_options.api_endpoint = self.DEFAULT_MTLS_ENDPOINT
        elif (use_mtls_env == 'auto'):
            has_client_cert_source = ((client_options.client_cert_source is not None) or mtls.has_default_client_cert_source())
            client_options.api_endpoint = (self.DEFAULT_MTLS_ENDPOINT if has_client_cert_source else self.DEFAULT_ENDPOINT)
        else:
            raise MutualTLSChannelError('Unsupported GOOGLE_API_USE_MTLS value. Accepted values: never, auto, always')
    if isinstance(transport, JobServiceTransport):
        if (credentials or client_options.credentials_file):
            raise ValueError('When providing a transport instance, provide its credentials directly.')
        if client_options.scopes:
            raise ValueError('When providing a transport instance, provide its scopes directly.')
        self._transport = transport
    else:
        Transport = type(self).get_transport_class(transport)
        self._transport = Transport(credentials=credentials, credentials_file=client_options.credentials_file, host=client_options.api_endpoint, scopes=client_options.scopes, api_mtls_endpoint=client_options.api_endpoint, client_cert_source=client_options.client_cert_source, quota_project_id=client_options.quota_project_id)