func (c *Client) NewDeviceSubscription(ctx context.Context, deviceID string, handle SubscriptionHandler) (*DeviceSubscription, error) {
	return NewDeviceSubscription(ctx, deviceID, handle, handle, c.gateway)
}
NewDeviceSubscription creates new devices subscriptions to listen events: resource published, resource unpublished.
JWT token must be stored in context for grpc call.
package client
import (
	"context"
	"github.com/plgd-dev/hub/grpc-gateway/pb"
)
type DeviceSubscription struct {
	id  string
	sub *DeviceSubscriptions
}