Generates an implementation of a user-defined interface T that
extends
com.google.gwt.user.client.ui.ImageBundle .
Each method in T must be declared to return
com.google.gwt.user.client.ui.AbstractImagePrototype , take no
parameters, and optionally specify the metadata tag gwt.resource
as the name of an image that can be found in the classpath. In the absence of
the metatadata tag, the method name with an extension of
.png, .jpg, or .gif defines the name of the image, and the
image file must be located in the same package as T.