WSH_WSHRDINV_XMLP_PKG

May I know why below view can return the value of WSH_WSHRDINV_XMLP_PKG.CP_ship_to_addr2_p? As i found the package WSH_WSHRDINV_XMLP_PKG of function CP_SHIP_TO_ADDR2_P which only include a statement ('return cp_ship_to_add2') and no any statement for getting the value.

CREATE OR REPLACE FORCE VIEW "APPS"."LSG_V_RPT_PICKING_LIST_HK" ("ORG_ID", "DELIVERY_ID3", "DELIVERY_ID_CHR", "DELIVERY_NAME", "SHIP_DATE", "SCHEDULE_SHIP_DATE", "CURRENCY_CODE", "ROUTE", "SHIP_METHOD_CODE", "GROSS_WEIGHT", "WEIGHT_UOM_CODE", "NUM_LPN", "COUNTRY_OF_ORIGIN", "FROM_ADDR1", "FROM_ADDR2", "FROM_ADDR3", "FROM_ADDR4", "FROM_CITY_STATE", "FROM_COUNTRY", "TO_ADDR1", "TO_ADDR2", "TO_ADDR3", "TO_ADDR4", "TO_CITY_STATE", "TO_COUNTRY", "CATEGORY", "ITEM_COST", "EXTENDED_COST", "ORGANIZATION_ID", "ITEM_CODE", "INVENTORY_ITEM_ID", "LOT_NUMBER", "CUSTOMER_ITEM_ID", "ORDERED_QUANTITY", "ORDER_QUANTITY_UOM", "SHIPPED_QUANTITY", "UNIT_OF_MEASURE", "PO", "ORDER_NUMBER", "HEADER_ID10", "SOURCE_HEADER_ID_CHR", "LINE_ID", "SOURCE_LINE_ID_CHR", "SHIP_TO_SITE_USE_ID", "SHIP_TO_CONTACT_ID", "SOURCE_UOM", "SOURCE_CODE", "ITEM_DESCRIPTION", "TOP_MODEL_LINE_ID10", "ATO_LINE_ID", "SHIPPING_INSTRUCTIONS", "CUST_PO_NUMBER", "WAYBILL", "DELIVERY_DETAIL_ID10", "DELIVERY_DETAIL_ID_CHR", "C_NUM_BOXES", "C_DATA_FOUND", "CF_CUSTOMER_NAME", "CUSTOMER_NUMBER", "F_SHIP_TO_CUST_NAME", "CP_SHIP_TO_ADDR1", "CP_SHIP_TO_ADDR2", "CP_SHIP_TO_ADDR3", "CP_SHIP_TO_ADDR4", "CP_SHIP_TO_CITY_STATE", "CP_SHIP_TO_COUNTRY", "CF_CONTACT_NAME", "CF_COMMODITY_CLASS", "C_ITEM_DISP", "CP_ITEM_COST", "CP_EXTENDED_COST", "RELEASED_STATUS") AS