getOrElse method Null safety

V getOrElse(
  1. K key,
  2. V defaultValue(
      )
    )

    Returns the value for the given key, or the result of the defaultValue function if there was no entry for the given key.

    Implementation

    V getOrElse(K key, V Function() defaultValue) {
      return get(key) ?? defaultValue();
    }