/** * Returns the value of this variable. */ public T get(Channel channel) { if (channel == null) { throw new NullPointerException("channel"); } T value = map.get(channel); if (value == null) { value = initialValue(channel); if (value != null) { T oldValue = setIfAbsent(channel, value); if (oldValue != null) { value = oldValue; } } } return value; }