def does_not_exist(self):
if not isinstance(self.val, str_types):<EOL><INDENT>raise TypeError('<STR_LIT>')<EOL><DEDENT>if os.path.exists(self.val):<EOL><INDENT>self._err('<STR_LIT>' % self.val)<EOL><DEDENT>return self<EOL>
Asserts that val is a path and that it does not exist.