How to use the cerberus.platform._str_type function in Cerberus

- the error-reference, see :mod:`cerberus.errors`

                     - arbitrary, supplemental information about the error

                     A :class:`~cerberus.errors.ValidationError` instance will
                     be created and added to
                     :attr:`~cerberus.Validator._errors`.
        """
        if len(args) == 1:
            self._errors.extend(args[0])
            self._errors.sort()
            for error in args[0]:
                self.document_error_tree.add(error)
                self.schema_error_tree.add(error)
                self.error_handler.emit(error)
        elif len(args) == 2 and isinstance(args[1], _str_type):
            self._error(args[0], errors.CUSTOM, args[1])
        elif len(args) >= 2:
            field = args[0]
            code = args[1].code
            rule = args[1].rule
            info = args[2:]

            document_path = self.document_path + (field,)

            schema_path = self.schema_path
            if code != errors.UNKNOWN_FIELD.code and rule is not None:
                schema_path += (field, rule)

            if not rule:
                constraint = None
            else:

:type error_handler: class or instance based on
                         :class:`~cerberus.errors.BaseErrorHandler` or
                         :class:`tuple`
    """  # noqa: E501

    mandatory_validations = ('nullable',)
    """ Rules that are evaluated on any field, regardless whether defined in
        the schema or not.
        Type: :class:`tuple` """
    priority_validations = ('nullable', 'readonly', 'type', 'empty')
    """ Rules that will be processed in that order before any other.
        Type: :class:`tuple` """
    types_mapping = {
        'binary': TypeDefinition('binary', (bytes, bytearray), ()),
        'boolean': TypeDefinition('boolean', (bool,), ()),
        'container': TypeDefinition('container', (Container,), (_str_type,)),
        'date': TypeDefinition('date', (date,), ()),
        'datetime': TypeDefinition('datetime', (datetime,), ()),
        'dict': TypeDefinition('dict', (Mapping,), ()),
        'float': TypeDefinition('float', (float, _int_types), ()),
        'integer': TypeDefinition('integer', (_int_types,), ()),
        'list': TypeDefinition('list', (Sequence,), (_str_type,)),
        'number': TypeDefinition('number', (_int_types, float), (bool,)),
        'set': TypeDefinition('set', (set,), ()),
        'string': TypeDefinition('string', (_str_type), ()),
    }
    """ This mapping holds all available constraints for the type rule and
        their assigned :class:`~cerberus.TypeDefinition`. """
    _valid_schemas = set()
    """ A :class:`set` of hashes derived from validation schemas that are
        legit for a particular ``Validator`` class. """

def _handle_schema_reference_for_validator(self, field, value):
        if not isinstance(value, _str_type):
            return value
        if value in self.known_schema_refs:
            raise _Abort

        self.known_schema_refs += (value,)
        definition = self.target_validator.schema_registry.get(value)
        if definition is None:
            path = self.document_path + (field,)
            self._error(path, 'Schema definition {} not found.'.format(value))
            raise _Abort
        return definition

def quote_string(value):
    if isinstance(value, _str_type):
        return '"%s"' % value
    else:
        return value

def _validate(self, schema):
        if isinstance(schema, _str_type):
            schema = self.validator.schema_registry.get(schema, schema)

        if schema is None:
            raise SchemaError(errors.SCHEMA_ERROR_MISSING)

        schema = copy(schema)
        for field in schema:
            if isinstance(schema[field], _str_type):
                schema[field] = rules_set_registry.get(schema[field], schema[field])

        if not self.schema_validator(schema, normalize=False):
            raise SchemaError(self.schema_validator.errors)

def _check_with_bulk_schema(self, field, value):
        # resolve schema registry reference
        if isinstance(value, _str_type):
            if value in self.known_rules_set_refs:
                return
            else:
                self.known_rules_set_refs.add(value)
            definition = self.target_validator.rules_set_registry.get(value)
            if definition is None:
                self._error(field, 'Rules set definition %s not found.' % value)
                return
            else:
                value = definition

        _hash = (
            mapping_hash({'turing': value}),
            mapping_hash(self.target_validator.types_mapping),
        )
        if _hash in self.target_validator._valid_schemas:

def _validate_allowed(self, allowed_values, field, value):
        """ {'type': 'container'} """
        if isinstance(value, Iterable) and not isinstance(value, _str_type):
            unallowed = set(value) - set(allowed_values)
            if unallowed:
                self._error(field, errors.UNALLOWED_VALUES, list(unallowed))
        else:
            if value not in allowed_values:
                self._error(field, errors.UNALLOWED_VALUE, value)

def compare_paths_lt(x, y):
    min_length = min(len(x), len(y))

    if x[:min_length] == y[:min_length]:
        return len(x) == min_length

    for i in range(min_length):
        a, b = x[i], y[i]

        for _type in (_int_types, _str_type, tuple):
            if isinstance(a, _type):
                if isinstance(b, _type):
                    break
                else:
                    return True

        if a == b:
            continue
        elif a < b:
            return True
        else:
            return False

    raise RuntimeError

:type error_handler: class or instance based on
                         :class:`~cerberus.errors.BaseErrorHandler` or
                         :class:`tuple`
    """  # noqa: E501

    mandatory_validations = ('nullable',)
    """ Rules that are evaluated on any field, regardless whether defined in
        the schema or not.
        Type: :class:`tuple` """
    priority_validations = ('nullable', 'readonly', 'type', 'empty')
    """ Rules that will be processed in that order before any other.
        Type: :class:`tuple` """
    types_mapping = {
        'binary': TypeDefinition('binary', (bytes, bytearray), ()),
        'boolean': TypeDefinition('boolean', (bool,), ()),
        'container': TypeDefinition('container', (Container,), (_str_type,)),
        'date': TypeDefinition('date', (date,), ()),
        'datetime': TypeDefinition('datetime', (datetime,), ()),
        'dict': TypeDefinition('dict', (Mapping,), ()),
        'float': TypeDefinition('float', (float, _int_types), ()),
        'integer': TypeDefinition('integer', (_int_types,), ()),
        'list': TypeDefinition('list', (Sequence,), (_str_type,)),
        'number': TypeDefinition('number', (_int_types, float), (bool,)),
        'set': TypeDefinition('set', (set,), ()),
        'string': TypeDefinition('string', (_str_type), ()),
    }
    """ This mapping holds all available constraints for the type rule and
        their assigned :class:`~cerberus.TypeDefinition`. """
    _valid_schemas = set()
    """ A :class:`set` of hashes derived from validation schemas that are
        legit for a particular ``Validator`` class. """

def _validate(self, schema):
        """ Validates a schema that defines rules against supported rules.

        :param schema: The schema to be validated as a legal cerberus schema
                       according to the rules of this Validator object.
        """
        if isinstance(schema, _str_type):
            schema = self.validator.schema_registry.get(schema, schema)

        if schema is None:
            raise SchemaError(errors.SCHEMA_ERROR_MISSING)

        schema = copy(schema)
        for field in schema:
            if isinstance(schema[field], _str_type):
                schema[field] = rules_set_registry.get(schema[field], schema[field])

        if not self.schema_validator(schema, normalize=False):
            raise SchemaError(self.schema_validator.errors)