/usr/share/doc/coccinelle-doc/examples/headers.iso is in coccinelle-doc 1.0.0~rc22.deb-1.
This file is owned by root:root, with mode 0o644.
The actual contents of the file can be viewed below.
1 2 3 4 5 6 | Expression
@ one @
expression E;
@@
f(E) => g(E)
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