We can then execute the following query, for example, to find out the
bits of code for which there is no information traced at runtime:

(This is an example for the "division" problem)

SELECT filename
FROM modified
WHERE fixer = "division"
AND filename NOT IN
  (SELECT filename
   FROM division)

The except_clause which are in the "try", "else", or "finally" sections
were detected by mistake.

This is a fixup for commit 3aded8e0.

':' is too common; it can be used in the filename.

This is a fixup for commit a73f5fea.

Note: fixers -> fixes, because of how test's `fixer_pkg` works.

This way, the ',' behaves like the old '/'. This change is introduced to
support division on multiple lines.

This id is a unique number that distinguishes callers from the same line.