public function getVariables()
    {
        $variableStats = [];

        foreach ($this->variablesToSkip as $branchNumber => $variables) {
            foreach ($variables as $variable => $one) {
                if (!isset($variableStats[$variable])) {
                    $variableStats[$variable] = 1;
                } else {
                    ++$variableStats[$variable];
                }
            }
        }

        $variables = [];
        $numberBranches = \count($this->branches);
        foreach ($variableStats as $variable => $number) {
            if ($number == $numberBranches) {
                $variables[] = $variable;
            }
        }

        return $variables;
    }