Extends IBaseLabelProvider with the methods
to provide the text and/or image for the label of a given element.
Used by most structured viewers, except table viewers.
Returns the image for the label of the given element. The image
is owned by the label provider and must not be disposed directly.
Instead, dispose the label provider when no longer needed.
Parameters:
element - the element for which to provide the label image
Returns:
the image used to label the element, or null
if there is no image for the given object