namespace? tests.import;
using;
using package;
using package.`module`.name::*;
using numpy as 女朋友
using `tensor-flow` as tfboys
using { };
using package {
project.first.{}
project::second::{}
};
using #Encode;
using @decode;
using serde.#Encode;
using serde::@decode;
using serde::{#Serialize, #`Deserialize`}
using serde::{@serialize, @`deserialize`}
using {
project.`class` as @`class`;
project.`union` as #`union`;
project.@`enumerate` as `enumerate`
project.#`interface` as `interface`
}