# Microsoft.Extensions.Configuration

``` diff
 namespace Microsoft.Extensions.Configuration {
     public class BinderOptions {
+        public bool ErrorOnUnknownConfiguration { get; set; }
     }
     public static class ConfigurationExtensions {
+        public static IConfigurationSection GetRequiredSection(this IConfiguration configuration, string key);
     }
+    public sealed class ConfigurationKeyNameAttribute : Attribute {
+        public ConfigurationKeyNameAttribute(string name);
+        public string Name { get; }
+    }
+    public sealed class ConfigurationManager : IConfiguration, IConfigurationBuilder, IConfigurationRoot, IDisposable {
+        public ConfigurationManager();
+        IDictionary<string, object> Microsoft.Extensions.Configuration.IConfigurationBuilder.Properties { get; }
+        IList<IConfigurationSource> Microsoft.Extensions.Configuration.IConfigurationBuilder.Sources { get; }
+        IEnumerable<IConfigurationProvider> Microsoft.Extensions.Configuration.IConfigurationRoot.Providers { get; }
+        public string this[string key] { get; set; }
+        public void Dispose();
+        public IEnumerable<IConfigurationSection> GetChildren();
+        public IConfigurationSection GetSection(string key);
+        IChangeToken Microsoft.Extensions.Configuration.IConfiguration.GetReloadToken();
+        IConfigurationBuilder Microsoft.Extensions.Configuration.IConfigurationBuilder.Add(IConfigurationSource source);
+        IConfigurationRoot Microsoft.Extensions.Configuration.IConfigurationBuilder.Build();
+        void Microsoft.Extensions.Configuration.IConfigurationRoot.Reload();
+    }
 }
```