<SYSTEM_TASK:>
Solve the following problem using Python, implementing the functions described below, one line at a time
<END_TASK>
<USER_TASK:>
Description:
 def get_vboxes(self):
 """ Get the maximum ID of the VBoxes :return: Maximum VBox ID :rtype: int """

        vbox_list = []
        vbox_max = None
        for node in self.nodes:
            if node['type'] == 'VirtualBoxVM':
                vbox_list.append(node['vbox_id'])

        if len(vbox_list) > 0:
            vbox_max = max(vbox_list)
        return vbox_max