Как следующий код обнаруживает перехват в iOS?

static func amIRuntimeHook(
    dyldAllowList: [String],
    detectionClass: AnyClass,
    selector: Selector,
    isClassMethod: Bool
  ) -> Bool {
    var method: Method?
    if isClassMethod {
      method = class_getClassMethod(detectionClass, selector)
    } else {
      method = class_getInstanceMethod(detectionClass, selector)
    }
    
    guard let method = method else {
      // method not found
      return true
    }
    
    let imp = method_getImplementation(method)
    var info = Dl_info()
    
    _ = swiftOnceDenyFishHooK
    
    // dladdr will look through vm range of allImages for vm range of an Image that contains pointer 
    // of method and return info of the Image
    if dladdr(UnsafeRawPointer(imp), &info) != 1 {
      return false
    }

Как dladdr(UnsafeRawPointer(imp), &info) != 1 гарантирует, что функция не подключена?

Ссылка: https://github.com/securing/IOSSecuritySuite/blob/master/IOSSecuritySuite/RuntimeHookChecker.swift