function getSectionForAnchor(sAnchorId) {
					var oAnchor = Element.getElementById(sAnchorId),
						sSectionId = oAnchor.getKey();
					return Element.getElementById(sSectionId);
				}
Maps the moved anchor to its corresponding section;
Also adjusts the index taking into consideration that there might be invisible sections

@param {object} mSpecificChangeInfo - Information needed to create the change
@param {object} mPropertyBag - Object additional properties like modifier or appComponent
@returns {Promise} resolves if change could be applied
@private