This is mostly about saving you from having to write ``timeout=None`` over and over :)  I think it's going to be really rare anybody needs to change the timeout for just one operation.  More likely we'll instantiate one of these classes and use the same timeout value for every call.  it's the opposite of DockerCmd where we're going to be calling it to do different things frequently.  This class will mostly be doing the same stuff over and over.