Advances the pointer forward to the last span in the sequence whose interval range has a value v such that
comp.directionToTargetFrom(v) >= 0.
This operation is O(log(cardinality)).
This operation never invalidates a valid cursor, it may only move it forward from its current position but
never exhaust it.
Note also search should only be called on a non-empty cursor, after having called hasNext() and next() at
least once.
Parameters:
comp - a Comparator used to search forward from the current span position.