func (s *ActionsService) GetWorkflowUsageByFileName(ctx context.Context, owner, repo, workflowFileName string) (*WorkflowUsage, *Response, error) {
	u := fmt.Sprintf("repos/%v/%v/actions/workflows/%v/timing", owner, repo, workflowFileName)
	return s.getWorkflowUsage(ctx, u)
}
GetWorkflowUsageByFileName gets a specific workflow usage by file name in the unit of billable milliseconds.

GitHub API docs: https://developer.github.com/v3/actions/workflows/#get-workflow-usage
package github
import (
	"context"
	"fmt"
)
type Workflow struct {
	ID        *int64     `json:"id,omitempty"`
	NodeID    *string    `json:"node_id,omitempty"`
	Name      *string    `json:"name,omitempty"`
	Path      *string    `json:"path,omitempty"`
	State     *string    `json:"state,omitempty"`
	CreatedAt *Timestamp `json:"created_at,omitempty"`
	UpdatedAt *Timestamp `json:"updated_at,omitempty"`
	URL       *string    `json:"url,omitempty"`
	HTMLURL   *string    `json:"html_url,omitempty"`
	BadgeURL  *string    `json:"badge_url,omitempty"`
}
type Workflows struct {
	TotalCount *int        `json:"total_count,omitempty"`
	Workflows  []*Workflow `json:"workflows,omitempty"`
}
type WorkflowUsage struct {
	Billable *WorkflowEnvironment `json:"billable,omitempty"`
}
type WorkflowEnvironment struct {
	Ubuntu  *WorkflowBill `json:"UBUNTU,omitempty"`
	MacOS   *WorkflowBill `json:"MACOS,omitempty"`
	Windows *WorkflowBill `json:"WINDOWS,omitempty"`
}
type WorkflowBill struct {
	TotalMS *int64 `json:"total_ms,omitempty"`
}
func (s *ActionsService) ListWorkflows(ctx context.Context, owner, repo string, opts *ListOptions) (*Workflows, *Response, error) {
	u := fmt.Sprintf("repos/%s/%s/actions/workflows", owner, repo)
	u, err := addOptions(u, opts)
	if err != nil {
		return nil, nil, err
	}
	req, err := s.client.NewRequest("GET", u, nil)
	if err != nil {
		return nil, nil, err
	}
	workflows := new(Workflows)
	resp, err := s.client.Do(ctx, req, &workflows)
	if err != nil {
		return nil, resp, err
	}
	return workflows, resp, nil
}
func (s *ActionsService) GetWorkflowByID(ctx context.Context, owner, repo string, workflowID int64) (*Workflow, *Response, error) {
	u := fmt.Sprintf("repos/%v/%v/actions/workflows/%v", owner, repo, workflowID)
	return s.getWorkflow(ctx, u)
}
func (s *ActionsService) GetWorkflowByFileName(ctx context.Context, owner, repo, workflowFileName string) (*Workflow, *Response, error) {
	u := fmt.Sprintf("repos/%v/%v/actions/workflows/%v", owner, repo, workflowFileName)
	return s.getWorkflow(ctx, u)
}
func (s *ActionsService) getWorkflow(ctx context.Context, url string) (*Workflow, *Response, error) {
	req, err := s.client.NewRequest("GET", url, nil)
	if err != nil {
		return nil, nil, err
	}
	workflow := new(Workflow)
	resp, err := s.client.Do(ctx, req, workflow)
	if err != nil {
		return nil, resp, err
	}
	return workflow, resp, nil
}
func (s *ActionsService) GetWorkflowUsageByID(ctx context.Context, owner, repo string, workflowID int64) (*WorkflowUsage, *Response, error) {
	u := fmt.Sprintf("repos/%v/%v/actions/workflows/%v/timing", owner, repo, workflowID)
	return s.getWorkflowUsage(ctx, u)
}