function onMouseMove(oEvent) {
			if (oExtension) {
				oHandle.append(oExtension);
				oHandle.extension = oExtension;
			}

			iNewWidth = (oEvent.clientX - iOverlayBoundary) * iDirectionFactor + iHalfOffsetWidth;

			iNewWidth = this._limitNewWidth(oOverlay, iNewWidth);

			// The middle of the handle is on the mouse cursor
			oHandle.style[sBeginDirection] = `${iNewWidth - oHandle.offsetWidth}px`;
		}
@param {sap.ui.dt.ElementOverlay} oOverlay - Overlay to be checked for editable
@return {Promise.<boolean>} <code>true</code> if it's editable wrapped in a promise.
@private
@override