public class FacebookExtension extends Extension {
...
}

...

private static List<Extension> extensions;

...

extensions = new ArrayList<Extension> ();
extensions.add (new org.haxe.extension.facebook.FacebookExtension ());

...

[javac] Compiling 4 source files to /Users/dokkogroup/Documents/haxe/extension-facebook-rest/test/Export/android/bin/bin/classes
    [javac] /Users/dokkogroup/Documents/haxe/extension-facebook-rest/test/Export/android/bin/src/org/haxe/lime/GameActivity.java:155: error: no suitable method found for add(FacebookExtension)
    [javac] 			extensions.add (new org.haxe.extension.facebook.FacebookExtension ());
    [javac] 			          ^
    [javac]     method Collection.add(Extension) is not applicable
    [javac]       (argument mismatch; FacebookExtension cannot be converted to Extension)
    [javac]     method List.add(Extension) is not applicable
    [javac]       (argument mismatch; FacebookExtension cannot be converted to Extension)
    [javac] Note: Some input files use or override a deprecated API.
    [javac] Note: Recompile with -Xlint:deprecation for details.
    [javac] Note: Some messages have been simplified; recompile with -Xdiags:verbose to get full output