"\u0000" = "null"
'\u0000' = "different key"
"\u0008 \u000c \U00000041 \u007f \u0080 \u00ff \ud7ff \ue000 \uffff \U00010000 \U0010ffff" = "escaped key"

"~ € ÿ ퟿  ￿ 𐀀 􏿿" = "basic key"
'l ~ € ÿ ퟿  ￿ 𐀀 􏿿' = "literal key"