Fix 'File Should Be Empty' doc to talk about files, not dirs.
@@ -549,7 +549,7 @@ class OperatingSystem:
self._link("File '%s' is empty.", path)
def file_should_not_be_empty(self, path, msg=None):
- """Fails if the specified directory is empty.
+ """Fails if the specified file is empty.
The default error message can be overridden with the ``msg`` argument.
"""
