diff --git a/test/Django-2.1.15/django/exceptions.py b/test/Django-2.1.15/django/exceptions.py
new file mode 100644
index 0000000..0e85397
--- /dev/null
+++ b/test/Django-2.1.15/django/exceptions.py
@@ -0,0 +1,183 @@
+"""
+Global Django exception and warning classes.
+"""
+
+
+class FieldDoesNotExist(Exception):
+    """The requested model field does not exist"""
+    pass
+
+
+class AppRegistryNotReady(Exception):
+    """The django.apps registry is not populated yet"""
+    pass
+
+
+class ObjectDoesNotExist(Exception):
+    """The requested object does not exist"""
+    silent_variable_failure = True
+
+
+class MultipleObjectsReturned(Exception):
+    """The query returned multiple objects when only one was expected."""
+    pass
+
+
+class SuspiciousOperation(Exception):
+    """The user did something suspicious"""
+
+
+class SuspiciousMultipartForm(SuspiciousOperation):
+    """Suspect MIME request in multipart form data"""
+    pass
+
+
+class SuspiciousFileOperation(SuspiciousOperation):
+    """A Suspicious filesystem operation was attempted"""
+    pass
+
+
+class DisallowedHost(SuspiciousOperation):
+    """HTTP_HOST header contains invalid value"""
+    pass
+
+
+class DisallowedRedirect(SuspiciousOperation):
+    """Redirect to scheme not in allowed list"""
+    pass
+
+
+class TooManyFieldsSent(SuspiciousOperation):
+    """
+    The number of fields in a GET or POST request exceeded
+    settings.DATA_UPLOAD_MAX_NUMBER_FIELDS.
+    """
+    pass
+
+
+class RequestDataTooBig(SuspiciousOperation):
+    """
+    The size of the request (excluding any file uploads) exceeded
+    settings.DATA_UPLOAD_MAX_MEMORY_SIZE.
+    """
+    pass
+
+
+class PermissionDenied(Exception):
+    """The user did not have permission to do that"""
+    pass
+
+
+class ViewDoesNotExist(Exception):
+    """The requested view does not exist"""
+    pass
+
+
+class MiddlewareNotUsed(Exception):
+    """This middleware is not used in this server configuration"""
+    pass
+
+
+class ImproperlyConfigured(Exception):
+    """Django is somehow improperly configured"""
+    pass
+
+
+class FieldError(Exception):
+    """Some kind of problem with a model field."""
+    pass
+
+
+NON_FIELD_ERRORS = '__all__'
+
+
+class ValidationError(Exception):
+    """An error while validating data."""
+    def __init__(self, message, code=None, params=None):
+        """
+        The `message` argument can be a single error, a list of errors, or a
+        dictionary that maps field names to lists of errors. What we define as
+        an "error" can be either a simple string or an instance of
+        ValidationError with its message attribute set, and what we define as
+        list or dictionary can be an actual `list` or `dict` or an instance
+        of ValidationError with its `error_list` or `error_dict` attribute set.
+        """
+        super().__init__(message, code, params)
+
+        if isinstance(message, ValidationError):
+            if hasattr(message, 'error_dict'):
+                message = message.error_dict
+            elif not hasattr(message, 'message'):
+                message = message.error_list
+            else:
+                message, code, params = message.message, message.code, message.params
+
+        if isinstance(message, dict):
+            self.error_dict = {}
+            for field, messages in message.items():
+                if not isinstance(messages, ValidationError):
+                    messages = ValidationError(messages)
+                self.error_dict[field] = messages.error_list
+
+        elif isinstance(message, list):
+            self.error_list = []
+            for message in message:
+                # Normalize plain strings to instances of ValidationError.
+                if not isinstance(message, ValidationError):
+                    message = ValidationError(message)
+                if hasattr(message, 'error_dict'):
+                    self.error_list.extend(sum(message.error_dict.values(), []))
+                else:
+                    self.error_list.extend(message.error_list)
+
+        else:
+            self.message = message
+            self.code = code
+            self.params = params
+            self.error_list = [self]
+
+    @property
+    def message_dict(self):
+        # Trigger an AttributeError if this ValidationError
+        # doesn't have an error_dict.
+        getattr(self, 'error_dict')
+
+        return dict(self)
+
+    @property
+    def messages(self):
+        if hasattr(self, 'error_dict'):
+            return sum(dict(self).values(), [])
+        return list(self)
+
+    def update_error_dict(self, error_dict):
+        if hasattr(self, 'error_dict'):
+            for field, error_list in self.error_dict.items():
+                error_dict.setdefault(field, []).extend(error_list)
+        else:
+            error_dict.setdefault(NON_FIELD_ERRORS, []).extend(self.error_list)
+        return error_dict
+
+    def __iter__(self):
+        if hasattr(self, 'error_dict'):
+            for field, errors in self.error_dict.items():
+                yield field, list(ValidationError(errors))
+        else:
+            for error in self.error_list:
+                message = error.message
+                if error.params:
+                    message %= error.params
+                yield str(message)
+
+    def __str__(self):
+        if hasattr(self, 'error_dict'):
+            return repr(dict(self))
+        return repr(list(self))
+
+    def __repr__(self):
+        return 'ValidationError(%s)' % self
+
+
+class EmptyResultSet(Exception):
+    """A database query predicate is impossible."""
+    pass
diff --git a/test/Django-2.1.15/django/paginator.py b/test/Django-2.1.15/django/paginator.py
new file mode 100644
index 0000000..4af80a2
--- /dev/null
+++ b/test/Django-2.1.15/django/paginator.py
@@ -0,0 +1,187 @@
+import collections.abc
+import warnings
+from math import ceil
+
+from django.utils.functional import cached_property
+from django.utils.translation import gettext_lazy as _
+
+
+class UnorderedObjectListWarning(RuntimeWarning):
+    pass
+
+
+class InvalidPage(Exception):
+    pass
+
+
+class PageNotAnInteger(InvalidPage):
+    pass
+
+
+class EmptyPage(InvalidPage):
+    pass
+
+
+class Paginator:
+
+    def __init__(self, object_list, per_page, orphans=0,
+                 allow_empty_first_page=True):
+        self.object_list = object_list
+        self._check_object_list_is_ordered()
+        self.per_page = int(per_page)
+        self.orphans = int(orphans)
+        self.allow_empty_first_page = allow_empty_first_page
+
+    def validate_number(self, number):
+        """Validate the given 1-based page number."""
+        try:
+            if isinstance(number, float) and not number.is_integer():
+                raise ValueError
+            number = int(number)
+        except (TypeError, ValueError):
+            raise PageNotAnInteger(_('That page number is not an integer'))
+        if number < 1:
+            raise EmptyPage(_('That page number is less than 1'))
+        if number > self.num_pages:
+            if number == 1 and self.allow_empty_first_page:
+                pass
+            else:
+                raise EmptyPage(_('That page contains no results'))
+        return number
+
+    def get_page(self, number):
+        """
+        Return a valid page, even if the page argument isn't a number or isn't
+        in range.
+        """
+        try:
+            number = self.validate_number(number)
+        except PageNotAnInteger:
+            number = 1
+        except EmptyPage:
+            number = self.num_pages
+        return self.page(number)
+
+    def page(self, number):
+        """Return a Page object for the given 1-based page number."""
+        number = self.validate_number(number)
+        bottom = (number - 1) * self.per_page
+        top = bottom + self.per_page
+        if top + self.orphans >= self.count:
+            top = self.count
+        return self._get_page(self.object_list[bottom:top], number, self)
+
+    def _get_page(self, *args, **kwargs):
+        """
+        Return an instance of a single page.
+
+        This hook can be used by subclasses to use an alternative to the
+        standard :cls:`Page` object.
+        """
+        return Page(*args, **kwargs)
+
+    @cached_property
+    def count(self):
+        """Return the total number of objects, across all pages."""
+        try:
+            return self.object_list.count()
+        except (AttributeError, TypeError):
+            # AttributeError if object_list has no count() method.
+            # TypeError if object_list.count() requires arguments
+            # (i.e. is of type list).
+            return len(self.object_list)
+
+    @cached_property
+    def num_pages(self):
+        """Return the total number of pages."""
+        if self.count == 0 and not self.allow_empty_first_page:
+            return 0
+        hits = max(1, self.count - self.orphans)
+        return ceil(hits / self.per_page)
+
+    @property
+    def page_range(self):
+        """
+        Return a 1-based range of pages for iterating through within
+        a template for loop.
+        """
+        return range(1, self.num_pages + 1)
+
+    def _check_object_list_is_ordered(self):
+        """
+        Warn if self.object_list is unordered (typically a QuerySet).
+        """
+        ordered = getattr(self.object_list, 'ordered', None)
+        if ordered is not None and not ordered:
+            obj_list_repr = (
+                '{} {}'.format(self.object_list.model, self.object_list.__class__.__name__)
+                if hasattr(self.object_list, 'model')
+                else '{!r}'.format(self.object_list)
+            )
+            warnings.warn(
+                'Pagination may yield inconsistent results with an unordered '
+                'object_list: {}.'.format(obj_list_repr),
+                UnorderedObjectListWarning,
+                stacklevel=3
+            )
+
+
+QuerySetPaginator = Paginator   # For backwards-compatibility.
+
+
+class Page(collections.abc.Sequence):
+
+    def __init__(self, object_list, number, paginator):
+        self.object_list = object_list
+        self.number = number
+        self.paginator = paginator
+
+    def __repr__(self):
+        return '<Page %s of %s>' % (self.number, self.paginator.num_pages)
+
+    def __len__(self):
+        return len(self.object_list)
+
+    def __getitem__(self, index):
+        if not isinstance(index, (int, slice)):
+            raise TypeError
+        # The object_list is converted to a list so that if it was a QuerySet
+        # it won't be a database hit per __getitem__.
+        if not isinstance(self.object_list, list):
+            self.object_list = list(self.object_list)
+        return self.object_list[index]
+
+    def has_next(self):
+        return self.number < self.paginator.num_pages
+
+    def has_previous(self):
+        return self.number > 1
+
+    def has_other_pages(self):
+        return self.has_previous() or self.has_next()
+
+    def next_page_number(self):
+        return self.paginator.validate_number(self.number + 1)
+
+    def previous_page_number(self):
+        return self.paginator.validate_number(self.number - 1)
+
+    def start_index(self):
+        """
+        Return the 1-based index of the first object on this page,
+        relative to total objects in the paginator.
+        """
+        # Special case, return zero if no items.
+        if self.paginator.count == 0:
+            return 0
+        return (self.paginator.per_page * (self.number - 1)) + 1
+
+    def end_index(self):
+        """
+        Return the 1-based index of the last object on this page,
+        relative to total objects found (hits).
+        """
+        # Special case for the last page because there can be orphans.
+        if self.number == self.paginator.num_pages:
+            return self.paginator.count
+        return self.number * self.paginator.per_page
diff --git a/test/Django-2.1.15/django/signals.py b/test/Django-2.1.15/django/signals.py
new file mode 100644
index 0000000..5d9618d
--- /dev/null
+++ b/test/Django-2.1.15/django/signals.py
@@ -0,0 +1,6 @@
+from django.dispatch import Signal
+
+request_started = Signal(providing_args=["environ"])
+request_finished = Signal()
+got_request_exception = Signal(providing_args=["request"])
+setting_changed = Signal(providing_args=["setting", "value", "enter"])
diff --git a/test/Django-2.1.15/django/signing.py b/test/Django-2.1.15/django/signing.py
new file mode 100644
index 0000000..1e92838
--- /dev/null
+++ b/test/Django-2.1.15/django/signing.py
@@ -0,0 +1,198 @@
+"""
+Functions for creating and restoring url-safe signed JSON objects.
+
+The format used looks like this:
+
+>>> signing.dumps("hello")
+'ImhlbGxvIg:1QaUZC:YIye-ze3TTx7gtSv422nZA4sgmk'
+
+There are two components here, separated by a ':'. The first component is a
+URLsafe base64 encoded JSON of the object passed to dumps(). The second
+component is a base64 encoded hmac/SHA1 hash of "$first_component:$secret"
+
+signing.loads(s) checks the signature and returns the deserialized object.
+If the signature fails, a BadSignature exception is raised.
+
+>>> signing.loads("ImhlbGxvIg:1QaUZC:YIye-ze3TTx7gtSv422nZA4sgmk")
+'hello'
+>>> signing.loads("ImhlbGxvIg:1QaUZC:YIye-ze3TTx7gtSv422nZA4sgmk-modified")
+...
+BadSignature: Signature failed: ImhlbGxvIg:1QaUZC:YIye-ze3TTx7gtSv422nZA4sgmk-modified
+
+You can optionally compress the JSON prior to base64 encoding it to save
+space, using the compress=True argument. This checks if compression actually
+helps and only applies compression if the result is a shorter string:
+
+>>> signing.dumps(list(range(1, 20)), compress=True)
+'.eJwFwcERACAIwLCF-rCiILN47r-GyZVJsNgkxaFxoDgxcOHGxMKD_T7vhAml:1QaUaL:BA0thEZrp4FQVXIXuOvYJtLJSrQ'
+
+The fact that the string is compressed is signalled by the prefixed '.' at the
+start of the base64 JSON.
+
+There are 65 url-safe characters: the 64 used by url-safe base64 and the ':'.
+These functions make use of all of them.
+"""
+
+import base64
+import datetime
+import json
+import re
+import time
+import zlib
+
+from django.conf import settings
+from django.utils import baseconv
+from django.utils.crypto import constant_time_compare, salted_hmac
+from django.utils.encoding import force_bytes
+from django.utils.module_loading import import_string
+
+_SEP_UNSAFE = re.compile(r'^[A-z0-9-_=]*$')
+
+
+class BadSignature(Exception):
+    """Signature does not match."""
+    pass
+
+
+class SignatureExpired(BadSignature):
+    """Signature timestamp is older than required max_age."""
+    pass
+
+
+def b64_encode(s):
+    return base64.urlsafe_b64encode(s).strip(b'=')
+
+
+def b64_decode(s):
+    pad = b'=' * (-len(s) % 4)
+    return base64.urlsafe_b64decode(s + pad)
+
+
+def base64_hmac(salt, value, key):
+    return b64_encode(salted_hmac(salt, value, key).digest()).decode()
+
+
+def get_cookie_signer(salt='django.core.signing.get_cookie_signer'):
+    Signer = import_string(settings.SIGNING_BACKEND)
+    key = force_bytes(settings.SECRET_KEY)  # SECRET_KEY may be str or bytes.
+    return Signer(b'django.http.cookies' + key, salt=salt)
+
+
+class JSONSerializer:
+    """
+    Simple wrapper around json to be used in signing.dumps and
+    signing.loads.
+    """
+    def dumps(self, obj):
+        return json.dumps(obj, separators=(',', ':')).encode('latin-1')
+
+    def loads(self, data):
+        return json.loads(data.decode('latin-1'))
+
+
+def dumps(obj, key=None, salt='django.core.signing', serializer=JSONSerializer, compress=False):
+    """
+    Return URL-safe, hmac/SHA1 signed base64 compressed JSON string. If key is
+    None, use settings.SECRET_KEY instead.
+
+    If compress is True (not the default), check if compressing using zlib can
+    save some space. Prepend a '.' to signify compression. This is included
+    in the signature, to protect against zip bombs.
+
+    Salt can be used to namespace the hash, so that a signed string is
+    only valid for a given namespace. Leaving this at the default
+    value or re-using a salt value across different parts of your
+    application without good cause is a security risk.
+
+    The serializer is expected to return a bytestring.
+    """
+    data = serializer().dumps(obj)
+
+    # Flag for if it's been compressed or not
+    is_compressed = False
+
+    if compress:
+        # Avoid zlib dependency unless compress is being used
+        compressed = zlib.compress(data)
+        if len(compressed) < (len(data) - 1):
+            data = compressed
+            is_compressed = True
+    base64d = b64_encode(data).decode()
+    if is_compressed:
+        base64d = '.' + base64d
+    return TimestampSigner(key, salt=salt).sign(base64d)
+
+
+def loads(s, key=None, salt='django.core.signing', serializer=JSONSerializer, max_age=None):
+    """
+    Reverse of dumps(), raise BadSignature if signature fails.
+
+    The serializer is expected to accept a bytestring.
+    """
+    # TimestampSigner.unsign() returns str but base64 and zlib compression
+    # operate on bytes.
+    base64d = TimestampSigner(key, salt=salt).unsign(s, max_age=max_age).encode()
+    decompress = base64d[:1] == b'.'
+    if decompress:
+        # It's compressed; uncompress it first
+        base64d = base64d[1:]
+    data = b64_decode(base64d)
+    if decompress:
+        data = zlib.decompress(data)
+    return serializer().loads(data)
+
+
+class Signer:
+
+    def __init__(self, key=None, sep=':', salt=None):
+        # Use of native strings in all versions of Python
+        self.key = key or settings.SECRET_KEY
+        self.sep = sep
+        if _SEP_UNSAFE.match(self.sep):
+            raise ValueError(
+                'Unsafe Signer separator: %r (cannot be empty or consist of '
+                'only A-z0-9-_=)' % sep,
+            )
+        self.salt = salt or '%s.%s' % (self.__class__.__module__, self.__class__.__name__)
+
+    def signature(self, value):
+        return base64_hmac(self.salt + 'signer', value, self.key)
+
+    def sign(self, value):
+        return '%s%s%s' % (value, self.sep, self.signature(value))
+
+    def unsign(self, signed_value):
+        if self.sep not in signed_value:
+            raise BadSignature('No "%s" found in value' % self.sep)
+        value, sig = signed_value.rsplit(self.sep, 1)
+        if constant_time_compare(sig, self.signature(value)):
+            return value
+        raise BadSignature('Signature "%s" does not match' % sig)
+
+
+class TimestampSigner(Signer):
+
+    def timestamp(self):
+        return baseconv.base62.encode(int(time.time()))
+
+    def sign(self, value):
+        value = '%s%s%s' % (value, self.sep, self.timestamp())
+        return super().sign(value)
+
+    def unsign(self, value, max_age=None):
+        """
+        Retrieve original value and check it wasn't signed more
+        than max_age seconds ago.
+        """
+        result = super().unsign(value)
+        value, timestamp = result.rsplit(self.sep, 1)
+        timestamp = baseconv.base62.decode(timestamp)
+        if max_age is not None:
+            if isinstance(max_age, datetime.timedelta):
+                max_age = max_age.total_seconds()
+            # Check timestamp is not older than max_age
+            age = time.time() - timestamp
+            if age > max_age:
+                raise SignatureExpired(
+                    'Signature age %s > %s seconds' % (age, max_age))
+        return value