assertNotNull(result, "Icon result should not be null for " + icon);

            // Result should be consistent with charset's canEncode capability
            boolean canEncode = StandardCharsets.ISO_8859_1.newEncoder().canEncode(icon.getUnicodeChar());
            String expected = canEncode ? String.valueOf(icon.getUnicodeChar()) : icon.getAsciiFallback();

     * @return the Unicode character if supported, otherwise the ASCII fallback
     */
    public String getIcon(Terminal terminal) {
        Charset charset = getTerminalCharset(terminal);
        return charset.newEncoder().canEncode(unicodeChar) ? String.valueOf(unicodeChar) : asciiFallback;
    }

    /**
     * Gets the charset used by the terminal for output.
     * Falls back to the system default charset if terminal charset is not available.