viewer.setContentProvider(new ArtifactsTreeContentProvider());
viewer.setLabelProvider(new ArtifactLabelProvider());
viewer.addSelectionChangedListener(new ArtifactTreeSelectionListener());
viewer.setContentProvider(new ArtifactsTreeContentProvider());
viewer.setLabelProvider(new ArtifactLabelProvider());
viewer.addSelectionChangedListener(new ArtifactTreeSelectionListener());