ECHO: "text_1bytes_len = ", "1234", " len = ", 4
ECHO: "text_2bytes_len = ", "ЛЛЛЛ", " len = ", 4
ECHO: "text_4bytes_len = ", "🂡🂱🃁🃑", " len = ", 4
ECHO: "[", 0, "] = ", "DEADBEEF", " of len=", 8, ":"
ECHO: "    [", 0, "]=", "D"
ECHO: "    [", 1, "]=", "E"
ECHO: "    [", 2, "]=", "A"
ECHO: "    [", 3, "]=", "D"
ECHO: "    [", 4, "]=", "B"
ECHO: "    [", 5, "]=", "E"
ECHO: "    [", 6, "]=", "E"
ECHO: "    [", 7, "]=", "F"
ECHO: "[", 1, "] = ", "Ленивый рыжий кот", " of len=", 17, ":"
ECHO: "    [", 0, "]=", "Л"
ECHO: "    [", 1, "]=", "е"
ECHO: "    [", 2, "]=", "н"
ECHO: "    [", 3, "]=", "и"
ECHO: "    [", 4, "]=", "в"
ECHO: "    [", 5, "]=", "ы"
ECHO: "    [", 6, "]=", "й"
ECHO: "    [", 7, "]=", " "
ECHO: "    [", 8, "]=", "р"
ECHO: "    [", 9, "]=", "ы"
ECHO: "    [", 10, "]=", "ж"
ECHO: "    [", 11, "]=", "и"
ECHO: "    [", 12, "]=", "й"
ECHO: "    [", 13, "]=", " "
ECHO: "    [", 14, "]=", "к"
ECHO: "    [", 15, "]=", "о"
ECHO: "    [", 16, "]=", "т"
ECHO: "[", 2, "] = ", "كسول الزنجبيل القط", " of len=", 18, ":"
ECHO: "    [", 0, "]=", "ك"
ECHO: "    [", 1, "]=", "س"
ECHO: "    [", 2, "]=", "و"
ECHO: "    [", 3, "]=", "ل"
ECHO: "    [", 4, "]=", " "
ECHO: "    [", 5, "]=", "ا"
ECHO: "    [", 6, "]=", "ل"
ECHO: "    [", 7, "]=", "ز"
ECHO: "    [", 8, "]=", "ن"
ECHO: "    [", 9, "]=", "ج"
ECHO: "    [", 10, "]=", "ب"
ECHO: "    [", 11, "]=", "ي"
ECHO: "    [", 12, "]=", "ل"
ECHO: "    [", 13, "]=", " "
ECHO: "    [", 14, "]=", "ا"
ECHO: "    [", 15, "]=", "ل"
ECHO: "    [", 16, "]=", "ق"
ECHO: "    [", 17, "]=", "ط"
ECHO: "[", 3, "] = ", "懶惰的姜貓", " of len=", 5, ":"
ECHO: "    [", 0, "]=", "懶"
ECHO: "    [", 1, "]=", "惰"
ECHO: "    [", 2, "]=", "的"
ECHO: "    [", 3, "]=", "姜"
ECHO: "    [", 4, "]=", "貓"
ECHO: "[", 4, "] = ", "äöü ÄÖÜ ß", " of len=", 9, ":"
ECHO: "    [", 0, "]=", "ä"
ECHO: "    [", 1, "]=", "ö"
ECHO: "    [", 2, "]=", "ü"
ECHO: "    [", 3, "]=", " "
ECHO: "    [", 4, "]=", "Ä"
ECHO: "    [", 5, "]=", "Ö"
ECHO: "    [", 6, "]=", "Ü"
ECHO: "    [", 7, "]=", " "
ECHO: "    [", 8, "]=", "ß"
ECHO: "[", 5, "] = ", "😁😂😃😄😅😆😇😈😉😊😋😌😍😎😏😐", " of len=", 16, ":"
ECHO: "    [", 0, "]=", "😁"
ECHO: "    [", 1, "]=", "😂"
ECHO: "    [", 2, "]=", "😃"
ECHO: "    [", 3, "]=", "😄"
ECHO: "    [", 4, "]=", "😅"
ECHO: "    [", 5, "]=", "😆"
ECHO: "    [", 6, "]=", "😇"
ECHO: "    [", 7, "]=", "😈"
ECHO: "    [", 8, "]=", "😉"
ECHO: "    [", 9, "]=", "😊"
ECHO: "    [", 10, "]=", "😋"
ECHO: "    [", 11, "]=", "😌"
ECHO: "    [", 12, "]=", "😍"
ECHO: "    [", 13, "]=", "😎"
ECHO: "    [", 14, "]=", "😏"
ECHO: "    [", 15, "]=", "😐"
ECHO: "[", 6, "] = ", "⠁⠂⠃⠄⠅⠆⠇⠈⠉⠊⠋⠌⠍⠎⠏", " of len=", 15, ":"
ECHO: "    [", 0, "]=", "⠁"
ECHO: "    [", 1, "]=", "⠂"
ECHO: "    [", 2, "]=", "⠃"
ECHO: "    [", 3, "]=", "⠄"
ECHO: "    [", 4, "]=", "⠅"
ECHO: "    [", 5, "]=", "⠆"
ECHO: "    [", 6, "]=", "⠇"
ECHO: "    [", 7, "]=", "⠈"
ECHO: "    [", 8, "]=", "⠉"
ECHO: "    [", 9, "]=", "⠊"
ECHO: "    [", 10, "]=", "⠋"
ECHO: "    [", 11, "]=", "⠌"
ECHO: "    [", 12, "]=", "⠍"
ECHO: "    [", 13, "]=", "⠎"
ECHO: "    [", 14, "]=", "⠏"
ECHO: "[", 7, "] = ", "🂡🂱🃁🃑", " of len=", 4, ":"
ECHO: "    [", 0, "]=", "🂡"
ECHO: "    [", 1, "]=", "🂱"
ECHO: "    [", 2, "]=", "🃁"
ECHO: "    [", 3, "]=", "🃑"
ECHO: "Past end of unicode only 2-byte ", undef
ECHO: "Past end of unicode only 4-byte ", undef
ECHO: "Past end of both 2-byte ", undef
ECHO: "Past end of both 4-byte ", undef