using testlo example of postgres source code

I work in linux
I want use testlo.c in client side that testlo.c is in src/test/example/
address of postgresql source code.
I run make in /src/test/example/
then copy executable file(testlo) in lib directory of installation
directory of postgresql.
now I don't know how do I can use this execute library?
how did I can an large object with this library(testlo)?