func (s *TasksCancelService) TaskId(taskId int64) *TasksCancelService {
	s.taskId = &taskId
	return s
}
TaskId specifies the task to cancel. Set to -1 to cancel all tasks.
package elastic
import (
	"fmt"
	"net/url"
	"strings"
	"gopkg.in/olivere/elastic.v3/uritemplates"
)
type TasksCancelService struct {
	client     *Client
	pretty     bool
	taskId     *int64
	actions    []string
	nodeId     []string
	parentNode string
	parentTask *int64
}
func NewTasksCancelService(client *Client) *TasksCancelService {
	return &TasksCancelService{
		client:  client,
		actions: make([]string, 0),
		nodeId:  make([]string, 0),
	}
}