2.1.11 [ECMA-262/5] Section 184.108.40.206, Number.prototype.toFixed (fractionDigits)
An implementation is permitted to extend the behaviour of toFixed for values of fractionDigits less than 0 or greater than 20. In this case toFixed would not necessarily throw RangeError for such values.
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If any value of the fractionDigits function is
converted to an integer and it is equal to
-∞, this value is treated as if it is