An instance of this class represents a loaded dll/shared
library, exporting functions using the standard C calling
convention (named 'cdecl' on Windows).
The exported functions can be accessed as attributes, or by
indexing with the function name. Examples:
<obj>.qsort -> callable object
<obj>['qsort'] -> callable object
Calling the functions releases the Python GIL during the call and
reacquires it afterwards.