/usr/lib/python2.7/dist-packages/imposm/parser/test/test.osm is in python-imposm-parser 1.0.7+ds-4.
This file is owned by root:root, with mode 0o777.
It is a symlink to /usr/lib/python2.7/dist-packages/imposm/parser/test/../../../../../../share/python-imposm-parser/tests/test.osm