该类内部维护了一个矩阵，是由俄罗斯方块抽象出来的 矩阵的每个元素代表方格中的每个单元格，1代表该格有方块，0没有 该类的所有方法都是围绕这个核心矩阵来操作的-internal safeguard such a matrix by Russian abstract squares of the matrix elements of each representative of each grid cells, a representative of the grid with squares 0 No such methods are all around this core to the operation of the matrix