src/Loader/PhpLoader.php
public function load()
    {
        $content = require $this->entity;

        if (is_callable($content)) {
            $content = call_user_func($content);
        }

        if (!is_array($content)) {
            throw new \RuntimeException(sprintf("'%s' does not return an array", $this->entity));
        }

        $this->content = $content;
        return $this;
    }
public function load()
    {
        $content = require $this->entity;

        if (is_callable($content)) {
            $content = call_user_func($content);
        }

        if (!is_array($content)) {
            throw new \RuntimeException(sprintf("'%s' does not return an array", $this->entity));
        }

        $this->content = $content;
        return $this;
    }
{@inheritdoc}

@throws \RuntimeException If the php file doesn't return an array