toNegativeUnicode method
The negative Unicode representation of this num.
Example:
1.1.toNegativeUnicode() == '1.1'
0.toNegativeUnicode() == '0'
(-5).toNegativeUnicode() == '−5'
Implementation
String toNegativeUnicode() => isNegative ? '$minusSign${-this}' : '$this';