src/Baum/Move.php
protected function bound2() {
    if ( !is_null($this->_bound2) ) return $this->_bound2;

    $this->_bound2 = (($this->bound1() > $this->node->getRight()) ? $this->node->getRight() + 1 : $this->node->getLeft() - 1);
    return $this->_bound2;
  }
protected function bound2() {
    if ( !is_null($this->_bound2) ) return $this->_bound2;

    $this->_bound2 = (($this->bound1() > $this->node->getRight()) ? $this->node->getRight() + 1 : $this->node->getLeft() - 1);
    return $this->_bound2;
  }
Computes the other boundary.
TODO: Maybe find a better name for this... ¿?

@return int