upgradeRequested

    pub fn upgradeRequested(request: *const Request) UpgradeRequest {
        switch (request.head.version) {
            .@"HTTP/1.0" => return .none,
            .@"HTTP/1.1" => if (request.head.method != .GET) return .none,
        }

        var sec_websocket_key: ?[]const u8 = null;
        var upgrade_name: ?[]const u8 = null;
        var it = request.iterateHeaders();
        while (it.next()) |header| {
            if (std.ascii.eqlIgnoreCase(header.name, "sec-websocket-key")) {
                sec_websocket_key = header.value;
            } else if (std.ascii.eqlIgnoreCase(header.name, "upgrade")) {
                upgrade_name = header.value;
            }
        }

        const name = upgrade_name orelse return .none;
        if (std.ascii.eqlIgnoreCase(name, "websocket")) return .{ .websocket = sec_websocket_key };
        return .{ .other = name };
    }