def METHOD_NAME(
    contexts: Mapping[str, Any]
) -> Tuple[Sequence[str], Sequence[str]]:
    context_keys = []
    context_values = []
    valid_types = (int, float, str)
    for ctx_name, ctx_obj in contexts.items():
        if isinstance(ctx_obj, dict):
            ctx_obj.pop("type", None)  # ignore type alias
            for inner_ctx_name, ctx_value in ctx_obj.items():
                if isinstance(ctx_value, valid_types):
                    value = _unicodify(ctx_value)
                    if value:
                        ctx_key = f"{ctx_name}.{inner_ctx_name}"
                        unicode_key = _unicodify(ctx_key)
                        unicode_value = _unicodify(ctx_value)
                        assert isinstance(unicode_key, str)
                        assert isinstance(unicode_value, str)
                        context_keys.append(unicode_key)
                        context_values.append(unicode_value)
    return (context_keys, context_values)