indexWhere method
Get element
's index in this set
Applying start
to define where index find first
Return -1
if not found, and the index is refer to the first element
found in this set
Implementation
int indexWhere(YearMonth element, [int start = 0]) {
for (int idx = start; idx < _ymr.length; idx++) {
if (_ymr.elementAt(idx) == element) return idx;
}
return -1;
}