func (s *RefreshService) Do(ctx context.Context) (*RefreshResult, error) {
	path, params, err := s.buildURL()
	if err != nil {
		return nil, err
	}
	res, err := s.client.PerformRequest(ctx, PerformRequestOptions{
		Method:  "POST",
		Path:    path,
		Params:  params,
		Headers: s.headers,
	})
	if err != nil {
		return nil, err
	}
	ret := new(RefreshResult)
	if err := s.client.decoder.Decode(res.Body, ret); err != nil {
		return nil, err
	}
	return ret, nil
}
Do executes the request.
package elastic
import (
	"context"
	"fmt"
	"net/http"
	"net/url"
	"strings"
	"github.com/olivere/elastic/v7/uritemplates"
)
type RefreshService struct {
	client *Client
	pretty     *bool        
	human      *bool        
	errorTrace *bool        
	filterPath []string     
	headers    http.Header  
	index []string
}
func NewRefreshService(client *Client) *RefreshService {
	builder := &RefreshService{
		client: client,
	}
	return builder
}
func (s *RefreshService) Pretty(pretty bool) *RefreshService {
	s.pretty = &pretty
	return s
}
func (s *RefreshService) Human(human bool) *RefreshService {
	s.human = &human
	return s
}
func (s *RefreshService) ErrorTrace(errorTrace bool) *RefreshService {
	s.errorTrace = &errorTrace
	return s
}
func (s *RefreshService) FilterPath(filterPath ...string) *RefreshService {
	s.filterPath = filterPath
	return s
}
func (s *RefreshService) Header(name string, value string) *RefreshService {
	if s.headers == nil {
		s.headers = http.Header{}
	}
	s.headers.Add(name, value)
	return s
}
func (s *RefreshService) Headers(headers http.Header) *RefreshService {
	s.headers = headers
	return s
}
func (s *RefreshService) Index(index ...string) *RefreshService {
	s.index = append(s.index, index...)
	return s
}
func (s *RefreshService) buildURL() (string, url.Values, error) {
	var err error
	var path string
	if len(s.index) > 0 {
		path, err = uritemplates.Expand("/{index}/_refresh", map[string]string{
			"index": strings.Join(s.index, ","),
		})
	} else {
		path = "/_refresh"
	}
	if err != nil {
		return "", url.Values{}, err
	}
	params := url.Values{}
	if v := s.pretty; v != nil {
		params.Set("pretty", fmt.Sprint(*v))
	}
	if v := s.human; v != nil {
		params.Set("human", fmt.Sprint(*v))
	}
	if v := s.errorTrace; v != nil {
		params.Set("error_trace", fmt.Sprint(*v))
	}
	if len(s.filterPath) > 0 {
		params.Set("filter_path", strings.Join(s.filterPath, ","))
	}
	return path, params, nil
}