/**
  * @covers ::getAlternativeSigns
  * @covers ::setAlternativeSigns
  */
 function testGetAlternativeSigns()
 {
     $alternative_signs = ['A', 'B'];
     $this->assertSame($this->sut, $this->sut->setAlternativeSigns($alternative_signs));
     $this->assertSame($alternative_signs, $this->sut->getAlternativeSigns());
 }