added constant TRAILING_LITERALS
added constant TRAILING_LITERALS

which is more explicit than its value `3`.
reported by @terrelln

unknownbrackets/maxcso,unknownbrackets/maxcso,unknownbrackets/maxcso,unknownbrackets/maxcso,unknownbrackets/maxcso,unknownbrackets/maxcso,unknownbrackets/maxcso