We don't ever use it and its deprecated.
#include <deal.II/base/utilities.h>
#include <algorithm>
-#include <iterator>
#include <vector>
#include <deal.II/base/template_constraints.h>
-#include <iterator>
-
-
DEAL_II_NAMESPACE_OPEN
#include <deal.II/base/complex_overloads.h>
#include <complex>
-#include <iterator>
#include <utility>
DEAL_II_NAMESPACE_OPEN
# include <atomic>
# include <functional>
# include <future>
-# include <iterator>
# include <list>
# include <memory>
# include <mutex>
#include <algorithm>
#include <initializer_list>
#include <iosfwd>
-#include <iterator>
#include <vector>
DEAL_II_NAMESPACE_OPEN
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