Connect

• returns Boolean

Source

res.__defineGetter__('headerSent', function(){
    return this._header;
  });

res.setHeader()

• String field
• String val

Source

res.setHeader = function(field, val){
    var key = field.toLowerCase()
      , prev;

    // special-case Set-Cookie
    if (this._headers && 'set-cookie' == key) {
      if (prev = this.getHeader(field)) {
        val = Array.isArray(prev)
          ? prev.concat(val)
          : [prev, val];
      }
    // charset
    } else if ('content-type' == key && this.charset) {
      val += '; charset=' + this.charset;
    }

    return setHeader.call(this, field, val);
  };

res._renderHeaders()

Source

res._renderHeaders = function(){
    if (!this._emittedHeader) this.emit('header');
    this._emittedHeader = true;
    return _renderHeaders.call(this);
  };

  res.writeHead = function(){
    if (!this._emittedHeader) this.emit('header');
    this._emittedHeader = true;
    return writeHead.apply(this, arguments);
  };

  res._hasConnectPatch = true;
}