# System.Composition

``` diff
+namespace System.Composition {
+    public abstract class CompositionContext {
+        protected CompositionContext();
+        public object GetExport(CompositionContract contract);
+        public object GetExport(Type exportType);
+        public object GetExport(Type exportType, string contractName);
+        public TExport GetExport<TExport>();
+        public TExport GetExport<TExport>(string contractName);
+        public IEnumerable<object> GetExports(Type exportType);
+        public IEnumerable<object> GetExports(Type exportType, string contractName);
+        public IEnumerable<TExport> GetExports<TExport>();
+        public IEnumerable<TExport> GetExports<TExport>(string contractName);
+        public abstract bool TryGetExport(CompositionContract contract, out object export);
+        public bool TryGetExport(Type exportType, out object export);
+        public bool TryGetExport(Type exportType, string contractName, out object export);
+        public bool TryGetExport<TExport>(string contractName, out TExport export);
+        public bool TryGetExport<TExport>(out TExport export);
+    }
+    public static class CompositionContextExtensions {
+        public static void SatisfyImports(this CompositionContext compositionContext, object objectWithLooseImports);
+        public static void SatisfyImports(this CompositionContext compositionContext, object objectWithLooseImports, AttributedModelProvider conventions);
+    }
+    public sealed class Export<T> : IDisposable {
+        public Export(T value, Action disposeAction);
+        public T Value { get; }
+        public void Dispose();
+    }
+    public class ExportAttribute : Attribute {
+        public ExportAttribute();
+        public ExportAttribute(string contractName);
+        public ExportAttribute(string contractName, Type contractType);
+        public ExportAttribute(Type contractType);
+        public string ContractName { get; private set; }
+        public Type ContractType { get; private set; }
+    }
+    public class ExportFactory<T> {
+        public ExportFactory(Func<Tuple<T, Action>> exportCreator);
+        public Export<T> CreateExport();
+    }
+    public class ExportFactory<T, TMetadata> : ExportFactory<T> {
+        public ExportFactory(Func<Tuple<T, Action>> exportCreator, TMetadata metadata);
+        public TMetadata Metadata { get; }
+    }
+    public sealed class ExportMetadataAttribute : Attribute {
+        public ExportMetadataAttribute(string name, object value);
+        public string Name { get; private set; }
+        public object Value { get; private set; }
+    }
+    public class ImportAttribute : Attribute {
+        public ImportAttribute();
+        public ImportAttribute(string contractName);
+        public bool AllowDefault { get; set; }
+        public string ContractName { get; private set; }
+    }
+    public sealed class ImportingConstructorAttribute : Attribute {
+        public ImportingConstructorAttribute();
+    }
+    public class ImportManyAttribute : Attribute {
+        public ImportManyAttribute();
+        public ImportManyAttribute(string contractName);
+        public string ContractName { get; private set; }
+    }
+    public sealed class ImportMetadataConstraintAttribute : Attribute {
+        public ImportMetadataConstraintAttribute(string name, object value);
+        public string Name { get; }
+        public object Value { get; }
+    }
+    public sealed class MetadataAttributeAttribute : Attribute {
+        public MetadataAttributeAttribute();
+    }
+    public sealed class OnImportsSatisfiedAttribute : Attribute {
+        public OnImportsSatisfiedAttribute();
+    }
+    public class PartMetadataAttribute : Attribute {
+        public PartMetadataAttribute(string name, object value);
+        public string Name { get; private set; }
+        public object Value { get; private set; }
+    }
+    public sealed class PartNotDiscoverableAttribute : Attribute {
+        public PartNotDiscoverableAttribute();
+    }
+    public class SharedAttribute : PartMetadataAttribute {
+        public SharedAttribute();
+        public SharedAttribute(string sharingBoundaryName);
+        public string SharingBoundary { get; }
+    }
+    public sealed class SharingBoundaryAttribute : Attribute {
+        public SharingBoundaryAttribute(params string[] sharingBoundaryNames);
+        public ReadOnlyCollection<string> SharingBoundaryNames { get; }
+    }
+}
```