Feature: A way to construct a `Network` object for an existing docker network

What are you trying to do?

Attach a DockerContainer to an existing network. In my specific case, the network was created as part of a composable setup, and I'd like to attach a new container to that network.

Why should it be done this way?

I suppose my suggestion would be a way to construct a Network object by simply passing the name in as an argument. Best I can tell that name property is all that is really needed when the DockerContainer is started.

A perhaps easier way might be to create a new class

class ExistingNetwork:
    def __init__(self, network_name: str):
        self.name = network_name

While this I think could be passed into DockerContainer.with_network & it seems to work, it might be better to have this inherit Network and explicitly override the other methods in the Network class to ensure they are not called.

从 core/testcontainers/core/network.py 中 Network 的 name 属性附近开始，并检查 DockerContainer.with_network。确定如何表示现有网络的名称而不创建或管理该网络，然后验证 DockerContainer 启动时可以连接到该网络。