code: def __get_posix_path(self):
          
          if os_sep_is_slash:
              return self
          else:
              entry = self.get()
              r = entry.get_path().replace(OS_SEP, '/')
              return SCons.Subst.SpecialAttrWrapper(r, entry.name + "_posix")
docs: Return the path with / as the path separator,
          regardless of platform.