Please write code that follows the UML in java. You will be implementing the Observer Pattern to create a scenario with watchman and city folk. Subject: Our subject is the watchman. They are hanging out at the watch tower. When they see trouble coming they play the trumpet. One trumpet call is a moderate warning, two calls is a sever warning. Before notifying the observers they display one of the following messages. "WARNING: $1$ trumpet was played!" "WARNING: $2$ trumpets were played!" Observers: Our observers are the town folk. We have a Teacher, a Shop Owner, and a Knight. When the watchman issue trumpet calls, they are going to act based on how many calls they hear. They will display the corresponding messages. Teacher: $1$ Trumpet Call: "Teacher: Helps get every kid home safe" $2$ Trumpet Calls: "Teacher: Brings all students to the underground shelter" Shop Owner: $1$ Trumpet Call: "Shop Owner: Close down shop and head home" $2$ Trumpet Calls: "Shop Owner: Drops everything and find nearest hideout" Knight: $1$ Trumpet Call: "Knight: Helps everyone get home safe" $2$ Trumpet Calls: "Knight: Prepares for battle" DRIVER: package observer; public class TownDriver public static void main$($String$[]$ args$)$ System.out.println$("$A Happy Little City"$)$; Watchman watchman $=$ new Watchman$()$; Observer fredrick $=$ new ShopOwner$($watchman$)$; Observer lillian $=$ new Teacher$($watchman$)$; Observer monte $=$ new Knight$($watchman$)$; System.out.println$("")$; watchman.issueWarning$(1)$; System.out.println$("")$; watchman.issueWarning$(2)$; OUTPUT EXAMPLE: A Happy Little City $$ WARNING: $1$ trumpet was played! Shop Owner: Close down shop and head home Teacher: Helps get every kid home safe Knight: Helps everyone get home safe $$ WARNING: $2$ trumpets were played! Shop Owner: Drops everything and find nearest hideout Teacher: Brings all students to the underground shelter Knight: Prepares for battle