/usr/include/OpenMS/CHEMISTRY/MASSDECOMPOSITION/IMS/ is in libopenms-dev 1.11.1-3.
This file is owned by root:root, with mode 0o755.
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/usr/include/OpenMS/CHEMISTRY/MASSDECOMPOSITION/IMS/IMSAlphabet.h
/usr/include/OpenMS/CHEMISTRY/MASSDECOMPOSITION/IMS/IMSAlphabetParser.h
/usr/include/OpenMS/CHEMISTRY/MASSDECOMPOSITION/IMS/IMSAlphabetTextParser.h
/usr/include/OpenMS/CHEMISTRY/MASSDECOMPOSITION/IMS/IMSElement.h
/usr/include/OpenMS/CHEMISTRY/MASSDECOMPOSITION/IMS/IMSIsotopeDistribution.h
/usr/include/OpenMS/CHEMISTRY/MASSDECOMPOSITION/IMS/IntegerMassDecomposer.h
/usr/include/OpenMS/CHEMISTRY/MASSDECOMPOSITION/IMS/MassDecomposer.h
/usr/include/OpenMS/CHEMISTRY/MASSDECOMPOSITION/IMS/RealMassDecomposer.h
/usr/include/OpenMS/CHEMISTRY/MASSDECOMPOSITION/IMS/Weights.h
/usr/include/OpenMS/CHEMISTRY/MASSDECOMPOSITION/IMS/sources.cmake