[BUGS] issue with C functions using pg_dump

i am am doing some test using the Adventureworks sample database (available on postgresql wiki) and i have noticed an issue with pgdump

pg_dump --dbname=postgresql://postgres:xxx@127.0.0.1:5432/Adventureworks --no-owner --format=plain --schema=public  --file="D:\public.sql"

the generated sql file does not contain the code of the LANGUAGE c functions stored in this schema

could you please confirm it's a bug ? 

regards