func: function addBoostFromTile(Tile _tile, address _attacker, address _defender, Boost memory _boost) pure private {
          if (_tile.claimer == _attacker) {
              require(_boost.attackBoost + _tile.blockValue >= _tile.blockValue); 
              _boost.attackBoost += _tile.blockValue;
              _boost.numAttackBoosts += 1;
          } else if (_tile.claimer == _defender) {
              require(_boost.defendBoost + _tile.blockValue >= _tile.blockValue); 
              _boost.defendBoost += _tile.blockValue;
              _boost.numDefendBoosts += 1;
          }
      }