Nodes of different colours represent the following:
Solid arrows point from a file to a file which it depends on. A file
is dependent upon another if the latter must be compiled before the former
can be.
program volatile_doctestuse stringifor_string_ttype(string)::astringastring='How are you?'print'(L1)',astring%encode(codec='base64')//''=='SG93IGFyZSB5b3U/'endprogram volatile_doctest