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diff --git a/tensorflow/compiler/xla/service/hlo_module_group.h b/tensorflow/compiler/xla/service/hlo_module_group.h
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+/* Copyright 2018 The TensorFlow Authors. All Rights Reserved.
+
+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.
+==============================================================================*/
+
+#ifndef TENSORFLOW_COMPILER_XLA_SERVICE_HLO_MODULE_GROUP_H_
+#define TENSORFLOW_COMPILER_XLA_SERVICE_HLO_MODULE_GROUP_H_
+
+#include <iosfwd>
+#include <string>
+#include <vector>
+
+#include "absl/strings/string_view.h"
+#include "absl/types/span.h"
+#include "tensorflow/compiler/xla/service/hlo.pb.h"
+#include "tensorflow/compiler/xla/service/hlo_module.h"
+
+namespace xla {
+
+// An abstraction representing a ordered set of HLO module built to run
+// concurrently across different devices.
+class HloModuleGroup {
+ public:
+  // Construct an empty module group.
+  explicit HloModuleGroup(absl::string_view name) : name_(name) {}
+
+  // Construct a module group containing a single module.
+  HloModuleGroup(absl::string_view name, std::unique_ptr<HloModule> module);
+
+  // Construct a module group containing any number of modules.
+  HloModuleGroup(absl::string_view name,
+                 absl::Span<std::unique_ptr<HloModule>> modules);
+
+  // Returns the modules contained in the group.
+  const std::vector<HloModule*>& modules() const { return module_ptrs_; }
+
+  // Returns a module at a particular index.
+  HloModule& module(int index) const { return *module_ptrs_.at(index); }
+
+  // Add a module to the back of vector of modules in the group.
+  void push_back(std::unique_ptr<HloModule> module);
+
+  // Moves all modules from the group into the returned vector. After this
+  // method runs, the module group will be empty.
+  std::vector<std::unique_ptr<HloModule>> ConsumeModules();
+
+  string name() const { return name_; }
+  string ToString() const;
+
+  // Serialize the module group to/from a proto.
+  HloModuleGroupProto ToProto() const;
+  static StatusOr<HloModuleGroup> CreateFromProto(
+      const HloModuleGroupProto& proto,
+      absl::Span<const HloModuleConfig> module_configs);
+
+ private:
+  string name_;
+
+  // Vector of modules as std::unique_ptrs.
+  std::vector<std::unique_ptr<HloModule>> modules_;
+
+  // Vector of modules as normal pointers. This vector is kept in sync with
+  // modules_ as modules are added to the group with push_back.
+  std::vector<HloModule*> module_ptrs_;
+};
+
+std::ostream& operator<<(std::ostream& out, const HloModuleGroup& group);
+
+}  // namespace xla
+
+#endif  // TENSORFLOW_COMPILER_XLA_SERVICE_HLO_MODULE_GROUP_H_