BlockLocationIterator 返回当前迭代的方块体积内的下一个方块位置。
BlockLocationIterator 用于抽象出其来源的方块体积的形状
（因此它可以表示构成矩形、立方体、球体、直线和复杂形状的所有方块位置）。
每次迭代都会返回父形状中的下一个有效方块位置。
除非父形状另有规定，BlockLocationIterator 将按照以下顺序遍历三维空间：
先按 X 轴递增，然后按 Z 轴递增，最后按 Y 轴递增。
（实际上是沿着 XZ 平面逐步移动，当该平面中的所有位置都遍历完后，
再增加 Y 坐标以进入下一个 XZ 切片）
A BlockLocationIterator returns the next block location of
the block volume across which it is iterating.
The BlockLocationIterator is used to abstract the shape of
the block volume it was fetched from (so it can represent
all the block locations that make up rectangles, cubes,
spheres, lines and complex shapes).
Each iteration pass returns the next valid block location in
the parent shape.
Unless otherwise specified by the parent shape - the
BlockLocationIterator will iterate over a 3D space in the
order of increasing X, followed by increasing Z followed by
increasing Y.
(Effectively stepping across the XZ plane, and when all the
locations in that plane are exhausted, increasing the Y
coordinate to the next XZ slice)
Checks if the underlining block volume has been invalidated.
Will return false if the block volume was modified between
creating the iterator and iterating it, and true otherwise.
BlockLocationIterator 返回当前迭代的方块体积内的下一个方块位置。 BlockLocationIterator 用于抽象出其来源的方块体积的形状 （因此它可以表示构成矩形、立方体、球体、直线和复杂形状的所有方块位置）。 每次迭代都会返回父形状中的下一个有效方块位置。 除非父形状另有规定，BlockLocationIterator 将按照以下顺序遍历三维空间： 先按 X 轴递增，然后按 Z 轴递增，最后按 Y 轴递增。 （实际上是沿着 XZ 平面逐步移动，当该平面中的所有位置都遍历完后， 再增加 Y 坐标以进入下一个 XZ 切片）
A BlockLocationIterator returns the next block location of the block volume across which it is iterating. The BlockLocationIterator is used to abstract the shape of the block volume it was fetched from (so it can represent all the block locations that make up rectangles, cubes, spheres, lines and complex shapes). Each iteration pass returns the next valid block location in the parent shape. Unless otherwise specified by the parent shape - the BlockLocationIterator will iterate over a 3D space in the order of increasing X, followed by increasing Z followed by increasing Y. (Effectively stepping across the XZ plane, and when all the locations in that plane are exhausted, increasing the Y coordinate to the next XZ slice)