Add support for HttpServer.defaultResponseHeaders to HttpMultiServer.

pkg/http_multi_server/lib/src/multi_headers.dart

+// Copyright (c) 2014, the Dart project authors.  Please see the AUTHORS file
+// for details. All rights reserved. Use of this source code is governed by a
+// BSD-style license that can be found in the LICENSE file.
+
+library http_multi_server.multi_headers;
+
+import 'dart:io';
+
+/// A class that delegates header access and setting to many [HttpHeaders]
+/// instances.
+class MultiHeaders implements HttpHeaders {
+  /// The wrapped headers.
+  final Set<HttpHeaders> _headers;
+
+  bool get chunkedTransferEncoding => _headers.first.chunkedTransferEncoding;
+  set chunkedTransferEncoding(bool value) {
+    for (var headers in _headers) {
+      headers.chunkedTransferEncoding = value;
+    }
+  }
+
+  int get contentLength => _headers.first.contentLength;
+  set contentLength(int value) {
+    for (var headers in _headers) {
+      headers.contentLength = value;
+    }
+  }
+
+  ContentType get contentType => _headers.first.contentType;
+  set contentType(ContentType value) {
+    for (var headers in _headers) {
+      headers.contentType = value;
+    }
+  }
+
+  DateTime get date => _headers.first.date;
+  set date(DateTime value) {
+    for (var headers in _headers) {
+      headers.date = value;
+    }
+  }
+
+  DateTime get expires => _headers.first.expires;
+  set expires(DateTime value) {
+    for (var headers in _headers) {
+      headers.expires = value;
+    }
+  }
+
+  String get host => _headers.first.host;
+  set host(String value) {
+    for (var headers in _headers) {
+      headers.host = value;
+    }
+  }
+
+  DateTime get ifModifiedSince => _headers.first.ifModifiedSince;
+  set ifModifiedSince(DateTime value) {
+    for (var headers in _headers) {
+      headers.ifModifiedSince = value;
+    }
+  }
+
+  bool get persistentConnection => _headers.first.persistentConnection;
+  set persistentConnection(bool value) {
+    for (var headers in _headers) {
+      headers.persistentConnection = value;
+    }
+  }
+
+  int get port => _headers.first.port;
+  set port(int value) {
+    for (var headers in _headers) {
+      headers.port = value;
+    }
+  }
+
+  MultiHeaders(Iterable<HttpHeaders> headers)
+      : _headers = headers.toSet();
+
+  void add(String name, Object value) {
+    for (var headers in _headers) {
+      headers.add(name, value);
+    }
+  }
+
+  void forEach(void f(String name, List<String> values)) =>
+      _headers.first.forEach(f);
+
+  void noFolding(String name) {
+    for (var headers in _headers) {
+      headers.noFolding(name);
+    }
+  }
+
+  void remove(String name, Object value) {
+    for (var headers in _headers) {
+      headers.remove(name);
+    }
+  }
+
+  void removeAll(String name) {
+    for (var headers in _headers) {
+      headers.removeAll(name, value);
+    }
+  }
+
+  void set(String name, Object value) {
+    for (var headers in _headers) {
+      headers.set(name, value);
+    }
+  }
+
+  String value(String name) => _headers.first.value(name);
+
+  List<String> operator[](String name) => _headers.first[name];
+}