diff --git a/internal/ceres/block_evaluate_preparer.h b/internal/ceres/block_evaluate_preparer.h
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+// Ceres Solver - A fast non-linear least squares minimizer
+// Copyright 2010, 2011, 2012 Google Inc. All rights reserved.
+// http://code.google.com/p/ceres-solver/
+//
+// Redistribution and use in source and binary forms, with or without
+// modification, are permitted provided that the following conditions are met:
+//
+// * Redistributions of source code must retain the above copyright notice,
+//   this list of conditions and the following disclaimer.
+// * Redistributions in binary form must reproduce the above copyright notice,
+//   this list of conditions and the following disclaimer in the documentation
+//   and/or other materials provided with the distribution.
+// * Neither the name of Google Inc. nor the names of its contributors may be
+//   used to endorse or promote products derived from this software without
+//   specific prior written permission.
+//
+// THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
+// AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
+// IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
+// ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR CONTRIBUTORS BE
+// LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
+// CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
+// SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
+// INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
+// CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
+// ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
+// POSSIBILITY OF SUCH DAMAGE.
+//
+// Author: keir@google.com (Keir Mierle)
+//
+// A evaluate preparer which puts jacobian the evaluated jacobian blocks
+// directly into their final resting place in an overall block sparse matrix.
+// The evaluator takes care to avoid evaluating the jacobian for fixed
+// parameters.
+
+#ifndef CERES_INTERNAL_BLOCK_EVALUATE_PREPARER_H_
+#define CERES_INTERNAL_BLOCK_EVALUATE_PREPARER_H_
+
+namespace ceres {
+namespace internal {
+
+class ResidualBlock;
+class SparseMatrix;
+
+class BlockEvaluatePreparer {
+ public:
+  // Using Init() instead of a constructor allows for allocating this structure
+  // with new[]. This is because C++ doesn't allow passing arguments to objects
+  // constructed with new[] (as opposed to plain 'new').
+  void Init(int** jacobian_layout);
+
+  // EvaluatePreparer interface
+
+  // Point the jacobian blocks directly into the block sparse matrix.
+  void Prepare(const ResidualBlock* residual_block,
+               int residual_block_index,
+               SparseMatrix* jacobian,
+               double** jacobians) const;
+
+ private:
+  int const* const* jacobian_layout_;
+};
+
+}  // namespace internal
+}  // namespace ceres
+
+#endif  // CERES_INTERNAL_BLOCK_EVALUATE_PREPARER_H_