  
      .. attribute:: content_type
  
          .. versionadded:: 1.5
              The ``content_type`` attribute was added.
  
          The content type to use for the response. ``content_type`` is passed
          as a keyword argument to ``response_class``. Default is ``None`` --
          meaning that Django uses :setting:`DEFAULT_CONTENT_TYPE`.
  
 
</s> remove         Historically, this parameter was only called ``mimetype`` (now
        deprecated), but since this is actually the value included in the HTTP
        ``Content-Type`` header, it can also include the character set
        encoding, which makes it more than just a MIME type specification. If
        ``mimetype`` is specified (not ``None``), that value is used.
        Otherwise, ``content_type`` is used. If neither is given,
        :setting:`DEFAULT_CONTENT_TYPE` is used.
 </s> add             Historically, this parameter was only called ``mimetype`` (now
            deprecated), but since this is actually the value included in the HTTP
            ``Content-Type`` header, it can also include the character set
            encoding, which makes it more than just a MIME type specification. If
            ``mimetype`` is specified (not ``None``), that value is used.
            Otherwise, ``content_type`` is used. If neither is given,
            :setting:`DEFAULT_CONTENT_TYPE` is used. </s> remove If fields in the serialized data do not exist on a model,
a ``DeserializationError`` will be raised unless the ``ignorenonexistent``
argument is passed in as True::
 </s> add     If fields in the serialized data do not exist on a model,
    a ``DeserializationError`` will be raised unless the ``ignorenonexistent``
    argument is passed in as True:: </s> remove This technique is fragile and was deprecated in Django 1.5. If you need the
response to be streamed from the iterator to the client, you should use the
:class:`StreamingHttpResponse` class instead.
 </s> add     This technique is fragile and was deprecated in Django 1.5. If you need the
    response to be streamed from the iterator to the client, you should use the
    :class:`StreamingHttpResponse` class instead. </s> remove The ability to pass a list of signals was added.
 </s> add     The ability to pass a list of signals was added. </s> remove As of Django 1.7, when :class:`HttpResponse` is instantiated with an
iterator, it will consume it immediately, store the response content as a
string, and discard the iterator.
 </s> add     As of Django 1.7, when :class:`HttpResponse` is instantiated with an
    iterator, it will consume it immediately, store the response content as a
    string, and discard the iterator.
  
      .. attribute:: content_type
  
          .. versionadded:: 1.5

  
          The content type to use for the response. ``content_type`` is passed
          as a keyword argument to ``response_class``. Default is ``None`` --
          meaning that Django uses :setting:`DEFAULT_CONTENT_TYPE`.
  
keep keep keep keep replace keep keep keep keep keep
 Adapted uses of versionchanged/versionadded to the new form.

Refs #20104. 
docs/ref/class-based-views/mixins-simple.txt