code: func NewStandardProvider(id *core.Identity) (*StandardProvider, error) {
  	if id == nil {
  		return nil, errors.New("transport: the identity hasn't been initialised. Has it been loaded from disk?")
  	}
  
  	paths := id.Profiles["paths"]
  	if paths == nil {
  		return &StandardProvider{}, nil
  	}
  
  	sp := &StandardProvider{
  		Paths: StandardPaths{
  			KeyFile:  paths["private_key"],
  			CertFile: paths["certificate"],
  		},
  	}
  
  	err := sp.Check()
  	if err != nil {
  		return nil, err
  	}
  
  	return sp, nil
  }
docs: // NewStandardProvider sets up new StandardProvider from the
  // information contained in an Identity.