<s>
Generation	B-General_Concept
gap	I-General_Concept
is	O
a	O
software	O
design	O
pattern	O
documented	O
by	O
John	O
Vlissides	O
that	O
treats	O
automatically	O
generated	O
code	O
differently	O
than	O
code	O
that	O
was	O
written	O
by	O
a	O
developer	B-Application
.	O
</s>
<s>
Modifications	O
should	O
not	O
be	O
made	O
to	O
generated	O
code	O
,	O
as	O
they	O
would	O
be	O
overwritten	O
if	O
the	O
code	O
generation	O
process	O
was	O
ever	O
re-run	O
,	O
such	O
as	O
during	O
recompilation	B-Language
.	O
</s>
<s>
The	O
developer	B-Application
would	O
then	O
hand-modify	O
a	O
concrete	O
implementation	O
of	O
the	O
generated	O
interface	O
.	O
</s>
