Change get agent data type from list

Author: spencer@primus

avapi/_dataset.py

@@ -134,7 +134,7 @@ def check_frame(self, frame):
     def get_agents(self, frame: int) -> "DataContainer":
         return self._load_agents(frame)
 
-    def get_agent(self, frame: int, agent: int) -> List[VehicleState]:
+    def get_agent(self, frame: int, agent: int) -> VehicleState:
         agents = self.get_agents(frame)
         return [ag for ag in agents if ag.ID == agent][0]