def setComponentByPosition(self, idx, value=None,
                               verifyConstraints=True,
                               exactTypes=False,
                               matchTags=True,
                               matchConstraints=True):
        l = len(self._componentValues)
        if idx >= l:
            self._componentValues = self._componentValues + (l+1-idx)*[None]
        if value is None:
            if self._componentValues[idx] is None:
                self._componentValues[idx] = self._componentType.getTypeByPosition(idx).clone()
                self._componentValuesSet = self._componentValuesSet + 1
            return self
        elif not isinstance(value, base.Asn1Item):
            t = self._componentType.getTypeByPosition(idx)
            if isinstance(t, base.AbstractSimpleAsn1Item):
                value = t.clone(value=value)
            else:
                raise error.PyAsn1Error('Instance value required')
        if verifyConstraints:
            if self._componentTypeLen:
                self._verifyComponent(idx, value)
            self._verifySubtypeSpec(value, idx)            
        if self._componentValues[idx] is None:
            self._componentValuesSet = self._componentValuesSet + 1
        self._componentValues[idx] = value
        return self
dataset/ETHPy150Open CouchPotato/CouchPotatoServer/libs/pyasn1/type/univ.py/SequenceAndSetBase.setComponentByPosition/swapped operands of `-`