Language: PHP
Label: safe
CWE: CWE-79 \u2014 Improper Neutralization of Input During Web Page Generation ('Cross-site Scripting')
The product does not neutralize or incorrectly neutralizes user-controllable input before it is placed in output that is used as a web page that is served to other users.

Code:
    public function assertIsLookup()
    {
        $this->assertIsArray();
        foreach ($this->contents as $v) {
            if ($v !== true) {
                $this->error('must be a lookup array');
            }
        }
        return $this;
    }