Note: This is not a real constructor, but just a description of the type of object that should be passed as
a parameter to some method(s), and/or the return value from some method(s).
In other words, the type exists only for documentation purposes, and you cannot call new number.__IntegerRegexpFlags()
second grouping, where separators 2..n have a different interval than the first separator (for India)
The character used as the thousands separator. Default is no
separator. For more than one symbol use an array, e.g. [",", ""],
makes ',' optional.
The leading plus-or-minus sign. Can be true, false, or [true,false].
Default is [true, false], (i.e. will match if it is signed
or unsigned).