Does Gerbil scheme require CLOSE[2] calls for 'duck type'[3] this-> 'gerbil of a program'[1] instances?
[0] : https://cons.io/
[1] : p239 "033 linker attempting to 'duck tape' this 'gerbil of a program'"https://progforperf.github.io/Expert_C_Programming.pdf
[2] : https://en.wikipedia.org/wiki/Common_Lisp_Object_System
[3] : https://ioflood.com/blog/duck-typing/ https://en.wikipedia.org/wiki/Duck_typing