where is the default auto-beam settings for 2/4 defined?

[Frédéric Bron]

In the following example, beams for 8 notes end at 1:4, 2:4, 3:4 and 4:4
but the only thing I can find in scm/auto-beam.scm  about time 2/4 is:

((end 1 32 2 4) . ,(ly:make-moment 1 8))
((end 1 32 2 4) . ,(ly:make-moment 2 8))
((end 1 32 2 4) . ,(ly:make-moment 3 8))    

How can I revert this rule to make 8 notes grouped by measure?

\version "2.12.2"
{ \time 2/4
 #(revert-auto-beam-setting '(end 1 8 2 4) 1 4) % does not work
 \repeat unfold 16 { c'8 }
}