Retrieves the zone-value associated with key
.
If this zone does not contain the value looks up the same key in the parent zone. If the key
is not found returns null
.
Any object can be used as key, as long as it has compatible operator ==
and hashCode
implementations. By controlling access to the key, a zone can grant or deny access to the zone value.
operator [](Object key);
© 2012 the Dart project authors
Licensed under the Creative Commons Attribution-ShareAlike License v4.0.
https://api.dartlang.org/stable/2.0.0/dart-async/Zone/operator_get.html