.. SPDX-FileCopyrightText: 2024 The IceTray Contributors
..
.. SPDX-License-Identifier: BSD-2-Clause

Make header files self-sufficient.
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Be sure that the path to your public header files, as seen from other
projects, makes sense.  Don't put #includes of tools in your header
files, otherwise I will have to add those tools to my ``USES_TOOLS``
when I use your project.