public function isTopFacingSurfaceSolid()
{
if ($this->isSolid()) {
return true;
} else {
if ($this instanceof Stair and ($this->getDamage() & 4) == 4) {
return true;
} elseif ($this instanceof Slab and ($this->getDamage() & 8) == 8) {
return true;
} elseif ($this instanceof SnowLayer and ($this->getDamage() & 7) == 7) {
return true;
}
}
return false;
}