src/Resource/ResourceProvider.php
private function addContent($content)
    {
        if ($this->relative) {
            $this->content = $this->mergeContents($this->content, $content);
        } else {
            $this->parent_content = $this->mergeContents($this->parent_content, $content);
        }
    }
private function addContent($content)
    {
        if ($this->relative) {
            $this->content = $this->mergeContents($this->content, $content);
        } else {
            $this->parent_content = $this->mergeContents($this->parent_content, $content);
        }
    }
Adds content to the parent contents

@param array $content The content from the resource