diff --git a/FFMpegCore/FFMPEG/Argument/ArgumentContainer.cs b/FFMpegCore/FFMPEG/Argument/ArgumentContainer.cs
index 829b511..60c0652 100644
--- a/FFMpegCore/FFMPEG/Argument/ArgumentContainer.cs
+++ b/FFMpegCore/FFMPEG/Argument/ArgumentContainer.cs
@@ -175,4 +175,20 @@ public bool Contains<T>() where T : Argument
             return false;
         }
     }
+
+
+    public class ArgumentBuilder
+    {
+        
+        
+        private ArgumentBuilder()
+        {
+            
+        }
+
+        public static ArgumentBuilder FromInputFile(string file)
+        {
+            
+        }
+    }
 }
diff --git a/FFMpegCore/FFMPEG/Argument/Atoms/ConcatArgument.cs b/FFMpegCore/FFMPEG/Argument/Atoms/ConcatArgument.cs
index 280153e..b68ec04 100644
--- a/FFMpegCore/FFMPEG/Argument/Atoms/ConcatArgument.cs
+++ b/FFMpegCore/FFMPEG/Argument/Atoms/ConcatArgument.cs
@@ -9,27 +9,18 @@ namespace FFMpegCore.FFMPEG.Argument
     /// Represents parameter of concat argument
     /// Used for creating video from multiple images or videos
     /// </summary>
-    public class ConcatArgument : Argument<IEnumerable<string>>, IEnumerable<string>
+    public class ConcatArgument : Argument<IEnumerable<string>>
     {
         public ConcatArgument() : base(new List<string>()) { }
 
         public ConcatArgument(IEnumerable<string> value) : base(value) { }
 
-        public IEnumerator<string> GetEnumerator()
-        {
-            return Value.GetEnumerator();
-        }
-
         /// <inheritdoc/>
         public override string GetStringValue()
         {
             return $"-i \"concat:{string.Join(@"|", Value)}\"";
         }
 
-        IEnumerator IEnumerable.GetEnumerator()
-        {
-            return GetEnumerator();
-        }
         public VideoInfo[] GetAsVideoInfo()
         {
             return Value.Select(v => new VideoInfo(v)).ToArray();
diff --git a/FFMpegCore/FFMPEG/Argument/Atoms/InputArgument.cs b/FFMpegCore/FFMPEG/Argument/Atoms/InputArgument.cs
index d421b0a..0c75e1a 100644
--- a/FFMpegCore/FFMPEG/Argument/Atoms/InputArgument.cs
+++ b/FFMpegCore/FFMPEG/Argument/Atoms/InputArgument.cs
@@ -1,6 +1,7 @@
 using System;
 using System.IO;
 using System.Linq;
+using System.Threading.Tasks;
 
 namespace FFMpegCore.FFMPEG.Argument
 {
@@ -29,4 +30,5 @@ public VideoInfo[] GetAsVideoInfo()
             return Value.Select(v => new VideoInfo(v)).ToArray();
         }
     }
+
 }
diff --git a/FFMpegCore/FFMpegCore.csproj b/FFMpegCore/FFMpegCore.csproj
index f400dc0..a0a66b5 100644
--- a/FFMpegCore/FFMpegCore.csproj
+++ b/FFMpegCore/FFMpegCore.csproj
@@ -1,7 +1,7 @@
 <Project Sdk="Microsoft.NET.Sdk">
 
   <PropertyGroup>
-    <TargetFramework>netstandard2.0</TargetFramework>
+    <TargetFramework>netstandard2.1</TargetFramework>
     <NeutralLanguage>en</NeutralLanguage>
     <RepositoryUrl>https://github.com/rosenbjerg/FFMpegCore</RepositoryUrl>
     <PackageProjectUrl>https://github.com/rosenbjerg/FFMpegCore</PackageProjectUrl>