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Solve the following problem using Python, implementing the functions described below, one line at a time
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Description:
 def _determine_spec(self, index):
 """ Determine how a value for a field should be constructed :param index: The field number :return: A tuple containing the following elements: - unicode string of the field name - Asn1Value class of the field spec - Asn1Value class of the value spec - None or dict of params to pass to the field spec - None or Asn1Value class indicating the value spec was derived from an OID or a spec callback """


        name, field_spec, field_params = self._fields[index]
        value_spec = field_spec
        spec_override = None

        if self._spec_callbacks is not None and name in self._spec_callbacks:
            callback = self._spec_callbacks[name]
            spec_override = callback(self)
            if spec_override:
                # Allow a spec callback to specify both the base spec and
                # the override, for situations such as OctetString and parse_as
                if spec_override.__class__ == tuple and len(spec_override) == 2:
                    field_spec, value_spec = spec_override
                    if value_spec is None:
                        value_spec = field_spec
                        spec_override = None
                # When no field spec is specified, use a single return value as that
                elif field_spec is None:
                    field_spec = spec_override
                    value_spec = field_spec
                    spec_override = None
                else:
                    value_spec = spec_override

        elif self._oid_nums is not None and self._oid_nums[1] == index:
            oid = self._lazy_child(self._oid_nums[0]).native
            if oid in self._oid_specs:
                spec_override = self._oid_specs[oid]
                value_spec = spec_override

        return (name, field_spec, value_spec, field_params, spec_override)