text: """HTTP Headers constants."""
  
  # After changing the file content call ./tools/gen.py
  # to regenerate the headers parser
  
  from multidict import istr
  
  METH_ANY = '*'
  METH_CONNECT = 'CONNECT'
  METH_HEAD = 'HEAD'
  METH_GET = 'GET'
  METH_DELETE = 'DELETE'
  METH_OPTIONS = 'OPTIONS'
  METH_PATCH = 'PATCH'
  METH_POST = 'POST'
  METH_PUT = 'PUT'
  METH_TRACE = 'TRACE'
  
  METH_ALL = {METH_CONNECT, METH_HEAD, METH_GET, METH_DELETE,
              METH_OPTIONS, METH_PATCH, METH_POST, METH_PUT, METH_TRACE}
  
  
  ACCEPT = istr('Accept')
  ACCEPT_CHARSET = istr('Accept-Charset')
  ACCEPT_ENCODING = istr('Accept-Encoding')
  ACCEPT_LANGUAGE = istr('Accept-Language')
  ACCEPT_RANGES = istr('Accept-Ranges')
  ACCESS_CONTROL_MAX_AGE = istr('Access-Control-Max-Age')
  ACCESS_CONTROL_ALLOW_CREDENTIALS = istr('Access-Control-Allow-Credentials')
  ACCESS_CONTROL_ALLOW_HEADERS = istr('Access-Control-Allow-Headers')
  ACCESS_CONTROL_ALLOW_METHODS = istr('Access-Control-Allow-Methods')
  ACCESS_CONTROL_ALLOW_ORIGIN = istr('Access-Control-Allow-Origin')
  ACCESS_CONTROL_EXPOSE_HEADERS = istr('Access-Control-Expose-Headers')
  ACCESS_CONTROL_REQUEST_HEADERS = istr('Access-Control-Request-Headers')
  ACCESS_CONTROL_REQUEST_METHOD = istr('Access-Control-Request-Method')
  AGE = istr('Age')
  ALLOW = istr('Allow')
  AUTHORIZATION = istr('Authorization')
  CACHE_CONTROL = istr('Cache-Control')
  CONNECTION = istr('Connection')
  CONTENT_DISPOSITION = istr('Content-Disposition')
  CONTENT_ENCODING = istr('Content-Encoding')
  CONTENT_LANGUAGE = istr('Content-Language')
  CONTENT_LENGTH = istr('Content-Length')
  CONTENT_LOCATION = istr('Content-Location')
  CONTENT_MD5 = istr('Content-MD5')
  CONTENT_RANGE = istr('Content-Range')
  CONTENT_TRANSFER_ENCODING = istr('Content-Transfer-Encoding')
  CONTENT_TYPE = istr('Content-Type')
  COOKIE = istr('Cookie')
  DATE = istr('Date')
  DESTINATION = istr('Destination')
  DIGEST = istr('Digest')
  ETAG = istr('Etag')
  EXPECT = istr('Expect')
  EXPIRES = istr('Expires')
  FORWARDED = istr('Forwarded')
  FROM = istr('From')
  HOST = istr('Host')
  IF_MATCH = istr('If-Match')
  IF_MODIFIED_SINCE = istr('If-Modified-Since')
  IF_NONE_MATCH = istr('If-None-Match')
  IF_RANGE = istr('If-Range')
  IF_UNMODIFIED_SINCE = istr('If-Unmodified-Since')
  KEEP_ALIVE = istr('Keep-Alive')
  LAST_EVENT_ID = istr('Last-Event-ID')
  LAST_MODIFIED = istr('Last-Modified')
  LINK = istr('Link')
  LOCATION = istr('Location')
  MAX_FORWARDS = istr('Max-Forwards')
  ORIGIN = istr('Origin')
  PRAGMA = istr('Pragma')
  PROXY_AUTHENTICATE = istr('Proxy-Authenticate')
  PROXY_AUTHORIZATION = istr('Proxy-Authorization')
  RANGE = istr('Range')
  REFERER = istr('Referer')
  RETRY_AFTER = istr('Retry-After')
  SEC_WEBSOCKET_ACCEPT = istr('Sec-WebSocket-Accept')
  SEC_WEBSOCKET_VERSION = istr('Sec-WebSocket-Version')
  SEC_WEBSOCKET_PROTOCOL = istr('Sec-WebSocket-Protocol')
  SEC_WEBSOCKET_EXTENSIONS = istr('Sec-WebSocket-Extensions')
  SEC_WEBSOCKET_KEY = istr('Sec-WebSocket-Key')
  SEC_WEBSOCKET_KEY1 = istr('Sec-WebSocket-Key1')
  SERVER = istr('Server')
  SET_COOKIE = istr('Set-Cookie')
  TE = istr('TE')
  TRAILER = istr('Trailer')
  TRANSFER_ENCODING = istr('Transfer-Encoding')
  UPGRADE = istr('Upgrade')
  WEBSOCKET = istr('WebSocket')
  URI = istr('URI')
  USER_AGENT = istr('User-Agent')
  VARY = istr('Vary')
  VIA = istr('Via')
  WANT_DIGEST = istr('Want-Digest')
  WARNING = istr('Warning')
  WWW_AUTHENTICATE = istr('WWW-Authenticate')
  X_FORWARDED_FOR = istr('X-Forwarded-For')
  X_FORWARDED_HOST = istr('X-Forwarded-Host')
  X_FORWARDED_PROTO = istr('X-Forwarded-Proto')
  