tasks/init/enyo/root/enyo/source/dom/Control.js
function(inName, inValue) {
		this.attributes[inName] = inValue;
		if (this.hasNode()) {
			this.attributeToNode(inName, inValue);
		}
		this.invalidateTags();
	}
function(inName, inValue) {
		this.attributes[inName] = inValue;
		if (this.hasNode()) {
			this.attributeToNode(inName, inValue);
		}
		this.invalidateTags();
	}
function ( inName , inValue ) { this . attributes [ inName ] = inValue ; if ( this . hasNode ( ) ) { this . attributeToNode ( inName , inValue ) ; } this . invalidateTags ( ) ; }
Sets the value of an attribute on this object. Pass null _inValue_ to remove an attribute.

set the tabIndex attribute for this DomNode
this.setAttribute("tabIndex", 3);
...
remove the index attribute
this.setAttribute("index", null);
Sets the value of an attribute on this object . Pass null _inValue_ to remove an attribute .