/usr/share/doc/libmac-widgets-java/api/com/explodingpixels/widgets/plaf/ is in libmac-widgets-doc 0.10.0+svn416-dfsg1-2.
This file is owned by root:root, with mode 0o755.
..
/usr/share/doc/libmac-widgets-java/api/com/explodingpixels/widgets/plaf/ButtonsSeparateScrollBarSkin.html
/usr/share/doc/libmac-widgets-java/api/com/explodingpixels/widgets/plaf/ButtonsTogetherScrollBarSkin.html
/usr/share/doc/libmac-widgets-java/api/com/explodingpixels/widgets/plaf/EPComboPopup.ComboBoxVerticalCenterProvider.html
/usr/share/doc/libmac-widgets-java/api/com/explodingpixels/widgets/plaf/EPComboPopup.html
/usr/share/doc/libmac-widgets-java/api/com/explodingpixels/widgets/plaf/EPTabPainter.CloseButtonLocation.html
/usr/share/doc/libmac-widgets-java/api/com/explodingpixels/widgets/plaf/EPTabPainter.html
/usr/share/doc/libmac-widgets-java/api/com/explodingpixels/widgets/plaf/EPTabbedPaneUI.html
/usr/share/doc/libmac-widgets-java/api/com/explodingpixels/widgets/plaf/ScrollBarOrientation.html
/usr/share/doc/libmac-widgets-java/api/com/explodingpixels/widgets/plaf/ScrollBarSkin.html
/usr/share/doc/libmac-widgets-java/api/com/explodingpixels/widgets/plaf/ScrollThumbImagePainter.html
/usr/share/doc/libmac-widgets-java/api/com/explodingpixels/widgets/plaf/SkinnableScrollBarUI.CustomArrowButtonListener.html
/usr/share/doc/libmac-widgets-java/api/com/explodingpixels/widgets/plaf/SkinnableScrollBarUI.ScrollBarSkinProvider.html
/usr/share/doc/libmac-widgets-java/api/com/explodingpixels/widgets/plaf/SkinnableScrollBarUI.html
/usr/share/doc/libmac-widgets-java/api/com/explodingpixels/widgets/plaf/package-frame.html
/usr/share/doc/libmac-widgets-java/api/com/explodingpixels/widgets/plaf/package-summary.html
/usr/share/doc/libmac-widgets-java/api/com/explodingpixels/widgets/plaf/package-tree.html