ion>Specifies if only one selected item at a time is allowed. </td></tr><tr class="SGroup SIndent1"><td class=SEntry><a href="#mxGraphSelectionModel.Functions" >Functions</a></td><td class=SDescription></td></tr><tr class="SFunction SIndent2 SMarked"><td class=SEntry><a href="#mxGraphSelectionModel.isSingleSelection" id=link10 onMouseOver="ShowTip(event, 'tt9', 'link10')" onMouseOut="HideTip('tt9')">isSingleSelection</a></td><td class=SDescription>Returns <a href="#mxGraphSelectionModel.singleSelection" cla