Behat\Gherkin\Parser::parseFeature PHP Method

    protected function parseFeature()
    {
        $token = $this->expectTokenType('Feature');
        $title = trim($token['value']) ?: null;
        $description = null;
        $tags = $this->popTags();
        $background = null;
        $scenarios = array();
        $keyword = $token['keyword'];
        $language = $this->lexer->getLanguage();
        $file = $this->file;
        $line = $token['line'];
        // Parse description, background, scenarios & outlines
        while ('EOS' !== $this->predictTokenType()) {
            $node = $this->parseExpression();
            if (is_string($node)) {
                $text = preg_replace('/^\\s{0,' . ($token['indent'] + 2) . '}|\\s*$/', '', $node);
                $description .= (null !== $description ? "\n" : '') . $text;
                continue;
            }
            if (!$background && $node instanceof BackgroundNode) {
                $background = $node;
                continue;
            }
            if ($node instanceof ScenarioInterface) {
                $scenarios[] = $node;
                continue;
            }
            if ($background instanceof BackgroundNode && $node instanceof BackgroundNode) {
                throw new ParserException(sprintf('Each Feature could have only one Background, but found multiple on lines %d and %d%s', $background->getLine(), $node->getLine(), $this->file ? ' in file: ' . $this->file : ''));
            }
            if (!$node instanceof ScenarioNode) {
                throw new ParserException(sprintf('Expected Scenario, Outline or Background, but got %s on line: %d%s', $node->getNodeType(), $node->getLine(), $this->file ? ' in file: ' . $this->file : ''));
            }
        }
        return new FeatureNode(rtrim($title) ?: null, rtrim($description) ?: null, $tags, $background, $scenarios, $keyword, $language, $file, $line);
    }