Advances to the first beyond the current whose document number is greater than or equal to
target. Returns the current document number or {@link #NO_MORE_DOCS} if there are no more docs in the set.
Behaves as if written:
int advance(int target) { int doc; while ((doc = nextDoc()) < target) { } return doc; }
Some implementations are considerably more efficient than that.
NOTE: certain implementations may return a different value (each time) if called several times in a row with the same target.
NOTE: this method may be called with {@value #NO_MORE_DOCS} forefficiency by some Scorers. If your implementation cannot efficiently determine that it should exhaust, it is recommended that you check for that value in each call to this method.
NOTE: after the iterator has exhausted you should not call this method, as it may result in unpredicted behavior.
@since 2.9