code: def mount(self, path, fs):
          # type: (Text, Union[FS, Text]) -> None
          
          if isinstance(fs, text_type):
              from .opener import open_fs
  
              fs = open_fs(fs)
  
          if not isinstance(fs, FS):
              raise TypeError("fs argument must be an FS object or a FS URL")
  
          if fs is self:
              raise ValueError("Unable to mount self")
          _path = forcedir(abspath(normpath(path)))
  
          for mount_path, _ in self.mounts:
              if _path.startswith(mount_path):
                  raise MountError("mount point overlaps existing mount")
  
          self.mounts.append((_path, fs))
          self.default_fs.makedirs(_path, recreate=True)
docs: Mounts a host FS object on a given path.
  
          Arguments:
              path (str): A path within the MountFS.
              fs (FS or str): A filesystem (instance or URL) to mount.