Add GoalSensor and component

com.unity.ml-agents/Runtime/Sensors/VectorSensor.cs

         }
 
         /// <inheritdoc/>
-        public SensorType GetSensorType()
+        public virtual SensorType GetSensorType()
         {
             return SensorType.Observation;
         }

Project/Assets/ML-Agents/Examples/SharedAssets/Scripts/GoalSensorComponent.cs

+using Unity.MLAgents.Sensors;
+
+
+public class GoalSensorComponent : SensorComponent
+{
+    public int observationSize;
+    public GoalSensor goalSensor;
+    /// <summary>
+    /// Creates a GoalSensor.
+    /// </summary>
+    /// <returns></returns>
+    public override ISensor CreateSensor()
+    {
+        goalSensor = new GoalSensor(observationSize);
+        return goalSensor;
+    }
+
+    /// <inheritdoc/>
+    public override int[] GetObservationShape()
+    {
+        return new[] { observationSize };
+    }
+
+    public void AddParameterizaton(float parameter)
+    {
+        if(goalSensor != null)
+        {
+            goalSensor.AddObservation(parameter);
+        }
+    }
+}
+
+public class GoalSensor : VectorSensor
+{
+
+    public GoalSensor(int observationSize, string name = null) : base(observationSize)
+    {
+        if (name == null)
+        {
+            name = $"GoalSensor_size{observationSize}";
+        }
+    }
+
+    public override SensorType GetSensorType()
+    {
+        return SensorType.Goal;
+    }
+}

Project/Assets/ML-Agents/Examples/SharedAssets/Scripts/GoalSensorComponent.cs.meta

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