def verifyShareFields(self, share, fields, tokens, index):
        if (len(fields) > 1) and ('value' in fields):
            msg = "ParseError: Field = 'value' within fields = '%s'" % (fields)
            raise excepting.ParseError(msg, tokens, index)

        if share: #does share have fields already
            for field in fields:
                if field not in share: #so this field could be added to share
                    if ('value' in share) or (field == 'value'):
                        msg = "ParseError: Candidate field '%s' when fields = '%s' exist" %\
                            (field, share.keys())
                        raise excepting.ParseError(msg, tokens, index)

        return
Convert a multinomial form into an expression.
dataset/ETHPy150Open ioflo/ioflo/ioflo/base/building.py/Builder.verifyShareFields--crossover with--dataset/ETHPy150Open sympy/sympy/sympy/polys/polyutils.py/expr_from_dict