I created today a CustomLabelProvider to parse a Date value from an ObjectProxy and pass it to a ComboBox. By mistake, i used it as i was using LabelProvider interface :
inside an interface ObjectProperties extends PropertyAccess<ObjectProxy>
The funny thing is that my class behaved exactly like an LabelProvider, the date value was recieved in the ComboBox, but was not formatted.
Maybe someone can have a closer look at this.