You are an expert in writing code in many different languages. Your goal is to perform code completion for the following code, keeping in mind the rest of the code and the file meta data.
    Metadata details:
    filename: threads_nested_attach_daemon.rs
    path of file: ./repos/jni-rs/tests
    
    the code of the file until where you have to start completion: #![cfg(feature = "invocation")]

mod util;
use util::{
    attach_current_thread, attach_current_thread_as_daemon, attach_current_thread_permanently,
    call_java_abs, jvm,
};

#[test]
pub fn nested_attaches_should_not_detach_daemon_t
    
pub fn nested_attaches_should_not_detach_daemon_thread() {
    assert_eq!(jvm().threads_attached(), 0);
    let mut env = unsafe { attach_current_thread_as_daemon() };
    let val = call_java_abs(&mut env, -1);
    assert_eq!(val, 1);
    assert_eq!(jvm().threads_attached(), 1);

    // Create nested AttachGuard.
    {
        let mut env_nested = attach_current_thread();
        let val = call_java_abs(&mut env_nested, -2);
        assert_eq!(val, 2);
        assert_eq!(jvm().threads_attached(), 1);
    }

    // Call a Java method after nested guard has been dropped to check that
    // this thread has not been detached.
    let val = call_java_abs(&mut env, -3);
    assert_eq!(val, 3);
    assert_eq!(jvm().threads_attached(), 1);

    // Nested attach_permanently is a no-op.
    {
        let mut env_nested = attach_current_thread_permanently();
        let val = call_java_abs(&mut env_nested, -4);
        assert_eq!(val, 4);
        assert_eq!(jvm().threads_attached(), 1);
    }
    assert_eq!(jvm().threads_attached(), 1);

    // Nested attach_as_daemon is a no-op.
    {
        let mut env_nested = unsafe { attach_current_thread_as_daemon() };
        let val = call_java_abs(&mut env_nested, -5);
        assert_eq!(val, 5);
        assert_eq!(jvm().threads_attached(), 1);
    }
    assert_eq!(jvm().threads_attached(), 1);
}