private static String malformedHeaderValueMessage(String value) {
        final StringBuilder buf = new StringBuilder(IntMath.saturatedAdd(value.length(), 64));
        buf.append("malformed header value: ");

        final int valueLength = value.length();
        for (int i = 0; i < valueLength; i++) {
            final char ch = value.charAt(i);
            if (PROHIBITED_VALUE_CHARS.get(ch)) {
                buf.append(PROHIBITED_VALUE_CHAR_NAMES[ch]);
            } else {
                buf.append(ch);
            }
        }

        return buf.toString();
    }
Creates a deep copy of the specified {@link HttpHeaderGetters}.
core/src/main/java/com/linecorp/armeria/common/HttpHeadersBase.java