isPrefixOf method
Whether every step of this sequence is a prefix of other — used to
warn about remap conflicts where one binding delays another
(e.g. g delays g g).
Implementation
bool isPrefixOf(KeySequence other) {
if (stepCount > other.stepCount) return false;
for (var index = 0; index < stepCount; index++) {
if (_stepAt(index) != other._stepAt(index)) return false;
}
return true;
}