code: func (apiDef *APIDefinition) GetSecurityScheme(name string) (SecurityScheme, bool) {
  	var ss SecurityScheme
  	var ok bool
  
  	// split library name by '.'
  	// if there is '.', it means we need to look from the library
  	splitted := strings.Split(strings.TrimSpace(name), ".")
  
  	switch len(splitted) {
  	case 1:
  		ss, ok = apiDef.SecuritySchemes[name]
  	case 2:
  		var l *Library
  		l, ok = apiDef.Libraries[splitted[0]]
  		if !ok {
  			return ss, false
  		}
  		ss, ok = l.SecuritySchemes[splitted[1]]
  	}
  	return ss, ok
  }
docs: // GetSecurityScheme gets security scheme by it's name
  // it also search in included library