Returns a 400 'bad request' response.

Returns an updated Ring response with the supplied charset added to the
Content-Type header.

Returns an updated Ring response with the a Content-Type header corresponding
to the given content-type.

Returns a Ring response for a HTTP 201 created response.

Returns a Ring response to serve a static file, or nil if an appropriate
file does not exist.
Options:
  :root            - take the filepath relative to this root path
  :index-files?    - look for index.* files in directories (defaults to true)
  :allow-symlinks? - allow symlinks that lead to paths outside the root path
                     (defaults to false)

Looks up a header in a Ring response (or request) case insensitively,
returning the header map entry, or nil if not present.

Gets the character encoding of a Ring response.

Looks up a header in a Ring response (or request) case insensitively,
returning the value of the header, or nil if not present.

Returns an updated Ring response with the specified header added.

Returns a 404 'not found' response.

Returns a Ring response for an HTTP 302 redirect. Status may be 
a key in redirect-status-codes or a numeric code. Defaults to 302

Returns a Ring response for an HTTP 303 redirect. Deprecated in favor
of using redirect with a :see-other status.

Map a keyword to a redirect status code.

Returns data about the resource specified by url, or nil if an
appropriate resource does not exist.

The return value is a map with optional values for:
:content        - the content of the URL, suitable for use as the :body
                  of a ring response
:content-length - the length of the :content, nil if not available
:last-modified  - the Date the :content was last modified, nil if not
                  available

This dispatches on the protocol of the URL as a keyword, and
implementations are provided for :file and :jar. If you are on a
platform where (Class/getResource) returns URLs with a different
protocol, you will need to provide an implementation for that
protocol.

This function is used internally by url-response.

Returns a Ring response to serve a packaged resource, or nil if the
resource does not exist.
Options:
  :root            - take the resource relative to this root
  :loader          - resolve the resource in this class loader
  :allow-symlinks? - allow symlinks that lead to paths outside the root
                     classpath directories (defaults to false)

Returns a skeletal Ring response with the given body, status of 200, and no
headers.

True if the supplied value is a valid response map.

Sets a cookie on the response. Requires the handler to be wrapped in the
wrap-cookies middleware.

Returns an updated Ring response with the given status.

Looks up a header in a Ring response (or request) case insensitively,
then updates the header with the supplied function and arguments in the
manner of update-in.

Return a response for the supplied URL.