public function testIsDiagonalZero() { $matrix = new Matrix(3, 3, 2); $sut = new Properties($matrix, 2); $this->assertTrue($sut->isDiagonalZero()); $matrix = new Matrix(3, 3, 2); $matrix->setPoint(3, 3, 3, 2); $sut = new Properties($matrix, 2); $this->assertFalse($sut->isDiagonalZero()); $matrix = new Matrix(1, 3, 2); $sut = new Properties($matrix, 2); $this->assertFalse($sut->isDiagonalZero()); }