@Override
    public ITextHover getTextHover(ISourceViewer sourceViewer, String contentType) {
        //return new BestMatchHover(this.getSQLEditor());
        return new SQLAnnotationHover(this.getSQLEditor());
    }
Returns the text hover which will provide the information to be shown
in a text hover popup window when requested for the given source viewer and
the given content type.

@see org.eclipse.jface.text.source.SourceViewerConfiguration#getTextHover(org.eclipse.jface.text.source.ISourceViewer, java.lang.String)
plugins/org.jkiss.dbeaver.ui.editors.sql/src/org/jkiss/dbeaver/ui/editors/sql/SQLEditorSourceViewerConfiguration.java