Fixed #20452 -- Rename 'headers' to 'header fields'.

    instantiated with an iterator. Django will consume and save the content of

    the iterator on first access.

Setting headers

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Setting header fields

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To set or remove a header in your response, treat it like a dictionary::

To set or remove a header field in your response, treat it like a dictionary::

    >>> response = HttpResponse()

    >>> response['Cache-Control'] = 'no-cache'

    >>> del response['Cache-Control']

Note that unlike a dictionary, ``del`` doesn't raise ``KeyError`` if the header

doesn't exist.

field doesn't exist.

HTTP headers cannot contain newlines. An attempt to set a header containing a

newline character (CR or LF) will raise ``BadHeaderError``

HTTP header fields cannot contain newlines. An attempt to set a header field

containing a newline character (CR or LF) will raise ``BadHeaderError``

Telling the browser to treat the response as a file attachment

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