PHPSA\Variable::isUnused PHP Method

    public function isUnused()
    {
        return $this->gets == 0 && $this->sets > 0;
    }

 public function testIsUnusedFalse()
 {
     $variable = new Variable('a', null, CompiledExpression::UNKNOWN);
     static::assertFalse($variable->isUnused());
 }