def METHOD_NAME():
    B = BlockMatrix([[MatrixSymbol(f'A_{i:d}{j:d}', 2, 2)
                      for j in range(3)]
                     for i in range(3)])
    assert B.blocks.shape == (3, 3)
    BB = reblock_2x2(B)
    assert BB.blocks.shape == (2, 2)
    assert B.shape == BB.shape
    assert B.as_explicit() == BB.as_explicit()