src/Node.php
public function setVariable(string $name, $value = null): self
    {
        $this->variables[$name] = $value;

        return $this;
    }
public function setVariable(string $name, $value = null): self
    {
        $this->variables[$name] = $value;

        return $this;
    }
public function setVariable ( string $ name , $ value = null ) : self { $ this -> variables [ $ name ] = $ value ; return $ this ; }
Set an arbitrary variable.
Set an arbitrary variable .