/usr/include/sbml/packages/layout/ is in libsbml5-dev 5.12.0+dfsg-3.
This file is owned by root:root, with mode 0o755.
..
/usr/include/sbml/packages/layout/common/
/usr/include/sbml/packages/layout/common/LayoutExtensionTypes.h
/usr/include/sbml/packages/layout/common/layoutfwd.h
/usr/include/sbml/packages/layout/extension/
/usr/include/sbml/packages/layout/extension/LayoutExtension.h
/usr/include/sbml/packages/layout/extension/LayoutModelPlugin.h
/usr/include/sbml/packages/layout/extension/LayoutSBMLDocumentPlugin.h
/usr/include/sbml/packages/layout/extension/LayoutSpeciesReferencePlugin.h
/usr/include/sbml/packages/layout/sbml/
/usr/include/sbml/packages/layout/sbml/BoundingBox.h
/usr/include/sbml/packages/layout/sbml/CompartmentGlyph.h
/usr/include/sbml/packages/layout/sbml/CubicBezier.h
/usr/include/sbml/packages/layout/sbml/Curve.h
/usr/include/sbml/packages/layout/sbml/Dimensions.h
/usr/include/sbml/packages/layout/sbml/GeneralGlyph.h
/usr/include/sbml/packages/layout/sbml/GraphicalObject.h
/usr/include/sbml/packages/layout/sbml/Layout.h
/usr/include/sbml/packages/layout/sbml/LineSegment.h
/usr/include/sbml/packages/layout/sbml/Point.h
/usr/include/sbml/packages/layout/sbml/ReactionGlyph.h
/usr/include/sbml/packages/layout/sbml/ReferenceGlyph.h
/usr/include/sbml/packages/layout/sbml/SpeciesGlyph.h
/usr/include/sbml/packages/layout/sbml/SpeciesReferenceGlyph.h
/usr/include/sbml/packages/layout/sbml/SpeciesReferenceRole.h
/usr/include/sbml/packages/layout/sbml/TextGlyph.h
/usr/include/sbml/packages/layout/util/
/usr/include/sbml/packages/layout/util/LayoutAnnotation.h
/usr/include/sbml/packages/layout/util/LayoutUtilities.h
/usr/include/sbml/packages/layout/validator/
/usr/include/sbml/packages/layout/validator/LayoutConsistencyValidator.h
/usr/include/sbml/packages/layout/validator/LayoutIdentifierConsistencyValidator.h
/usr/include/sbml/packages/layout/validator/LayoutSBMLError.h
/usr/include/sbml/packages/layout/validator/LayoutSBMLErrorTable.h
/usr/include/sbml/packages/layout/validator/LayoutValidator.h
/usr/include/sbml/packages/layout/validator/constraints/
/usr/include/sbml/packages/layout/validator/constraints/UniqueIdsLayout.h