public function getChildren()
    {
        $children = [];
        foreach ($this->children as $type) {
            foreach ($type as $child) {
                $children[] = $child;
            }
        }

        return $children;
    }
public function getChildren()
    {
        $children = [];
        foreach ($this->children as $type) {
            foreach ($type as $child) {
                $children[] = $child;
            }
        }

        return $children;
    }
public function getChildren ( ) { $ children = [ ] ; foreach ( $ this -> children as $ type ) { foreach ( $ type as $ child ) { $ children [ ] = $ child ; } } return $ children ; }
Return all child nodes.

Note that this will returned a flattened version
of the classes type => children map.

@return AbstractNode[]
Return all child nodes .