try {
            handshake();
        } catch (final IOException ex) {}
        return connection.getHeaderField(header);
    }

    private Map getHeaderFields0() {
        if (headerFields != null) {
            return headerFields;
        }
        final Map map = new HashMap();
        String key = connection.getHeaderFieldKey(0);

    }

    @Override
    public String getHeaderField(final String header) {
        handshake();
        return this.connection.getHeaderField(header);
    }

    private Map<String, List<String>> getHeaderFields0() {
        if (this.headerFields != null) {
            return this.headerFields;
        }
        final Map<String, List<String>> map = new HashMap<>();
        String key = this.connection.getHeaderFieldKey(0);