@Override
    public final String toString() {
        if (size == 0) {
            return endOfStream ? "[EOS]" : "[]";
        }

        final StringBuilder sb = new StringBuilder(7 + size * 20);
        if (endOfStream) {
            sb.append("[EOS, ");
        } else {
            sb.append('[');
        }

        for (Map.Entry<AsciiString, String> e : this) {
            sb.append(e.getKey()).append('=').append(e.getValue()).append(", ");
        }

        final int length = sb.length();
        sb.setCharAt(length - 2, ']');
        return sb.substring(0, length - 1);
    }
Adds the specified {@code setCookies} with {@link HttpHeaderNames#SET_COOKIE}.
core/src/main/java/com/linecorp/armeria/common/HttpHeadersBase.java