code: func (g *Gitlab) ProjectMergeRequestChanges(id, merge_request_id string) (*MergeRequestChanges, *ResponseMeta, error) {
  	u := g.ResourceUrl(ProjectMergeRequestChangesApiPath, map[string]string{
  		":id":               id,
  		":merge_request_id": merge_request_id,
  	})
  
  	var err error
  	changes := new(MergeRequestChanges)
  
  	contents, meta, err := g.buildAndExecRequest("GET", u.String(), nil)
  	if err == nil {
  		err = json.Unmarshal(contents, &changes)
  	}
  
  	return changes, meta, err
  }
docs: /*
  Get information about the merge request including its files and changes.
  
      GET /projects/:id/merge_request/:merge_request_id/changes
  
  Parameters:
  
      id               The ID of a project
      merge_request_id The ID of a merge request
  
  */