def __init__(self, *args, **kwargs):
        super().__init__(*args, **kwargs)
        f_lbl = self.fields['label']
        f_lbl.widget = forms.HiddenInput()
        # "forms" is the name of some Angular context object on the frontend.
        f_lbl.widget.attrs['ng-value'] = self.prefix % 'forms["%s"]'
        f_lbl.required = False
dataset/ETHPy150Open machinalis/iepy/iepy/webui/corpus/forms.py/EvidenceOnDocumentForm.__init__/swapped operands of `%`