code: func (it *Iterator) Seek(key []byte) (found bool) {
  	var next *node
  	_, next, found = it.seekForBaseSplice(key)
  	present := it.setNode(next, false)
  	return found && present
  }
docs: // Seek searches for the record with the given key. If it is present in the
  // skiplist, then Seek positions the iterator on that record and returns true.
  // If the record is not present, then Seek positions the iterator on the
  // following node (if it exists) and returns false.