Given the question: Information:  - China, officially the People's Republic of China (PRC), is a unitary sovereign state in East Asia. With a population of over 1.381 billion, it is the world's most populous country. The state is governed by the Communist Party of China, and its capital is Beijing. It exercises jurisdiction over 22 provinces, five autonomous regions, four direct-controlled municipalities (Beijing, Tianjin, Shanghai, and Chongqing), and two mostly self-governing special administrative regions (Hong Kong and Macau), and claims sovereignty over Taiwan. The country's major urban areas include Shanghai, Guangzhou, Beijing, Chongqing, Shenzhen, Tianjin and Hong Kong. China is a great power and a major regional power within Asia, and has been characterized as a potential superpower.  - Baoding is a city in Hebei province, China, approximately southwest of the national capital, Beijing. At the 2010 census, Baoding City had 11,194,372 inhabitants out of which 2,176,857 lived in the built-up ("or metro") area made of 3 urban districts and Qingyuan and Mancheng counties largely being conurbated, on . Baoding is among 13 Chinese cities with a population of over 10 million, ranking seventh.  - The Han dynasty was the second imperial dynasty of China (206 BC220 AD), preceded by the Qin dynasty (221206 BC) and succeeded by the Three Kingdoms period (220280 AD). Spanning over four centuries, the Han period is considered a golden age in Chinese history. To this day, China's majority ethnic group refers to itself as the "Han people" and the Chinese script is referred to as "Han characters". It was founded by the rebel leader Liu Bang, known posthumously as Emperor Gaozu of Han, and briefly interrupted by the Xin dynasty (923 AD) of the former regent Wang Mang. This interregnum separates the Han dynasty into two periods: the Western Han or Former Han (206 BC  9 AD) and the Eastern Han or Later Han (25220 AD).  - Northern China or North China (literally "China's north") is a geographical region of China. The heartland of North China is the North China Plain, or the Yellow River Plain. North China is usually restricted to the northern part of China proper (inner China and excludes Xinjiang and often Manchuria and the Northeast China.  - A prefecture (from the Latin "Praefectura") is an administrative jurisdiction or subdivision in any of various countries and within some international church structures, and in antiquity a Roman district governed by an appointed prefect.  - In many countries, a mayor (or , from the Latin "maior" , meaning "bigger") is the highest-ranking official in a municipal government such as that of a city or a town.  - A prefectural-level municipality, prefectural-level city or prefectural city is an administrative division of the People's Republic of China (PRC), ranking below a province and above a county in China's administrative structure. Prefectural level cities form the second level of the administrative structure (alongside prefectures, leagues and autonomous prefectures). Administrative chiefs (mayors) of prefectural level cities generally have the same rank as a division chief of a national ministry. Since the 1980s, most former prefectures have been renamed into prefectural level cities.  - Beijing (formerly romanised as Peking) is the capital of the People's Republic of China and the world's third most populous city proper. It is also one of the world's most populous capital cities. The city, located in northern China, is governed as a direct-controlled municipality under the national government with 16 urban, suburban, and rural districts. Beijing Municipality is surrounded by Hebei Province with the exception of neighbouring Tianjin Municipality to the southeast; together the three divisions form the Jingjinji metropolitan region and the national capital region of China.  - Hebei (postal: Hopeh) is a province of China in the North China region. Its one-character abbreviation is "" (Jì), named after Ji Province, a Han Dynasty province ("zhou") that included what is now southern Hebei. The name "Hebei" literally means "north of the river", referring to its location entirely to the north of the Huang He  (Yellow River).  - Xushui District ( simplified Chinese :  ; traditional Chinese :  ; pinyin : Xúshu Q ) is a district under the jurisdiction of Baoding prefecture - level city , Hebei , China .  - The Yellow River or Huang He is the second-longest river in Asia, following the Yangtze River, and the sixth-longest river system in the world at the estimated length of . Originating in the Bayan Har Mountains in Qinghai province of western China, it flows through nine provinces, and it empties into the Bohai Sea near the city of Dongying in Shandong province. The Yellow River basin has an eastwest extent of about and a northsouth extent of about . Its total basin area is about .    What is the relationship between 'xushui district' and 'county'?
The answer is:
instance of