function tokenURI(INonfungiblePositionManager positionManager, uint256 tokenId)
    external
    view
    override
    returns (string memory)
{
    // Missing token existence check
    (,, address token0, address token1, uint24 fee, int24 tickLower, int24 tickUpper,,,,,) =
      positionManager.positions(tokenId);
    // ...
}
function tokenURI(INonfungiblePositionManager positionManager, uint256 tokenId)
    external
    view
    override
    returns (string memory)
{
    require(positionManager.ownerOf(tokenId) != address(0), "URI query for nonexistent token");
    
    (,, address token0, address token1, uint24 fee, int24 tickLower, int24 tickUpper,,,,,) =
      positionManager.positions(tokenId);
    // ... rest of the function
}
