[Question] Is "REGISTRY" meant to be a decorator for "Collectors"?

Browsing through the code I've found a function called write_to_textfile in the exposition module. This function signature looks like this:

def write_to_textfile(path, registry):
    """Write metrics to the given path.
    pass

If you read the implementation of the function, turns out the expectation is not really a registry but instead anything that implements (something like an interface) the .collect() method.

Is that by design?

If so, would it be welcomed the addition of type hints throughout the code? I would be happy to add them and create a PR.

从 exposition 模块中的 write_to_textfile 开始，将其 registry 参数与 issue 中描述的 .collect() 行为进行比较。在进行更改之前，先确定是否需要为整个 Python 代码库添加类型提示；这需要就范围达成一致，并由 maintainer 作出决定。