method place-holders?!

[marco-foscato]

Hi,

I came across methods that were probably not supposed to be part of any stable release, as they just throw an exception saying that these methods are "not implemented".
See org.graphstream.ui.spriteManager.Sprite from release gs-core-1.3

public Iterator<String> getAttributeKeyIterator() {
	throw new RuntimeException("not implemented");
}

public Iterable<String> getEachAttributeKey() {
	return getAttributeKeySet();
}

public Collection<String> getAttributeKeySet() {
	throw new RuntimeException("not implemented");
}

public Map<String, Object> getAttributeMap() {
	throw new RuntimeException("not implemented");
}

This stuff is still there in the master branch as well as in release/2.0.0-beta