public static <T> void runOnceIfPresentOrOnChange(@Nonnull ObservableValue<T> value, @Nonnull Consumer<T> action) {
		T current = value.getValue();
		if (current != null) action.accept(current);
		else runOnceOnChange(value, action);
	}
Runs an action on the given observable's value if it is present <i>(non-null)</i>,
or once when it changes to another value.

@param value
		Value to observe.
@param action
		Action to run on the value.
@param <T>
		Value type.
recaf-ui/src/main/java/software/coley/recaf/util/NodeEvents.java