def METHOD_NAME(self, node):
    """ Register imported modules and usage symbols.  """
    module_path = tuple(node.module.split('.'))
    self.imports.add(module_path[0])
    for alias in node.names:
        path = module_path + (alias.name,)
        self.symbols[alias.asname or alias.name] = path
    self.update = True
    return None