From 84bdf38fe1b4ce39b49c0a8564a72b50daeb687b Mon Sep 17 00:00:00 2001
From: Reiley Yang <reyang@microsoft.com>
Date: Mon, 18 Oct 2021 10:12:08 -0700
Subject: [PATCH] Simplify code (#2491)

---
 .../Metrics/DropConfiguration.cs              | 35 -------------------
 .../Metrics/MetricStreamConfiguration.cs      |  9 +++++
 .../Metrics/MetricViewTests.cs                |  3 +-
 3 files changed, 11 insertions(+), 36 deletions(-)
 delete mode 100644 src/OpenTelemetry/Metrics/DropConfiguration.cs

diff --git a/src/OpenTelemetry/Metrics/DropConfiguration.cs b/src/OpenTelemetry/Metrics/DropConfiguration.cs
deleted file mode 100644
index 1245367219e..00000000000
--- a/src/OpenTelemetry/Metrics/DropConfiguration.cs
+++ /dev/null
@@ -1,35 +0,0 @@
-// <copyright file="DropConfiguration.cs" company="OpenTelemetry Authors">
-// Copyright The OpenTelemetry Authors
-//
-// Licensed under the Apache License, Version 2.0 (the "License");
-// you may not use this file except in compliance with the License.
-// You may obtain a copy of the License at
-//
-//     http://www.apache.org/licenses/LICENSE-2.0
-//
-// Unless required by applicable law or agreed to in writing, software
-// distributed under the License is distributed on an "AS IS" BASIS,
-// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
-// See the License for the specific language governing permissions and
-// limitations under the License.
-// </copyright>
-
-using System;
-
-namespace OpenTelemetry.Metrics
-{
-    internal class DropConfiguration : MetricStreamConfiguration
-    {
-        private Aggregation aggregation = Aggregation.Drop;
-
-        public override Aggregation Aggregation
-        {
-            get => this.aggregation;
-
-            set
-            {
-                throw new ArgumentException($"Aggregation cannot be set.");
-            }
-        }
-    }
-}
diff --git a/src/OpenTelemetry/Metrics/MetricStreamConfiguration.cs b/src/OpenTelemetry/Metrics/MetricStreamConfiguration.cs
index 3b60abe8bfa..4e5140510a0 100644
--- a/src/OpenTelemetry/Metrics/MetricStreamConfiguration.cs
+++ b/src/OpenTelemetry/Metrics/MetricStreamConfiguration.cs
@@ -41,5 +41,14 @@ public class MetricStreamConfiguration
         public virtual Aggregation Aggregation { get; set; }
 
         // TODO: MetricPoints caps can be configured here
+
+        private sealed class DropConfiguration : MetricStreamConfiguration
+        {
+            public override Aggregation Aggregation
+            {
+                get => Aggregation.Drop;
+                set { }
+            }
+        }
     }
 }
diff --git a/test/OpenTelemetry.Tests/Metrics/MetricViewTests.cs b/test/OpenTelemetry.Tests/Metrics/MetricViewTests.cs
index 7a825252513..c426e84b6c9 100644
--- a/test/OpenTelemetry.Tests/Metrics/MetricViewTests.cs
+++ b/test/OpenTelemetry.Tests/Metrics/MetricViewTests.cs
@@ -370,7 +370,8 @@ public void ViewToDropAndRetainInstrument()
         [Fact]
         public void MetricStreamConfigurationForDropMustNotAllowOverriding()
         {
-            Assert.Throws<ArgumentException>(() => MetricStreamConfiguration.Drop.Aggregation = Aggregation.Histogram);
+            MetricStreamConfiguration.Drop.Aggregation = Aggregation.Histogram;
+            Assert.Equal(Aggregation.Drop, MetricStreamConfiguration.Drop.Aggregation);
         }
     }
 #pragma warning restore SA1000 // KeywordsMustBeSpacedCorrectly