src/sap.ui.core/src/sap/ui/core/mvc/ControllerExtension.js
function(sId) {
				var sNamespace = this.getMetadata().getNamespace();
				sId = sNamespace + "." + sId;
				return this.base ? this.base.byId(sId) : undefined;
			}
function(sId) {
				var sNamespace = this.getMetadata().getNamespace();
				sId = sNamespace + "." + sId;
				return this.base ? this.base.byId(sId) : undefined;
			}
function ( sId ) { var sNamespace = this . getMetadata ( ) . getNamespace ( ) ; sId = sNamespace + "." + sId ; return this . base ? this . base . byId ( sId ) : undefined ; }
Returns an Element of the connected view with the given local ID.

Views automatically prepend their own ID as a prefix to created Elements
to make the IDs unique even in the case of multiple view instances.
For Controller extension the namespace of the control id gets also
prefixed with the namespace of the extension.
This method helps to find an element by its local ID only.

If no view is connected or if the view doesn't contain an element with
the given local ID, undefined is returned.

@param {string} sId View-local ID
@return {sap.ui.core.Element} Element by its (view local) ID
@public
Returns an Element of the connected view with the given local ID .