public function testAll()
 {
     $chess = new Chess('8/8/8/8/8/8/8/8 w KQkq - 0 1');
     $this->assertSame($chess->get('a1'), null);
     $this->assertSame($chess->get('a2'), null);
     $this->assertSame($chess->get('e4'), null);
     $this->assertSame($chess->get('g8'), null);
     $piece = ['type' => Chess::QUEEN, 'color' => Chess::WHITE];
     $chess->put($piece, 'e4');
     $this->assertSame($chess->get('e4'), $piece);
     $piece = ['type' => Chess::KING, 'color' => Chess::BLACK];
     $chess->put($piece, 'd3');
     $this->assertSame($chess->get('d3'), $piece);
     $chess->remove('d3');
     $this->assertSame($chess->get('d3'), null);
     $chess->remove('d3');
     $this->assertSame($chess->get('d3'), null);
 }