是否返回IEnumerable <>线程安全？

using System;
using System.Collections.Generic;
using System.Threading;

public class MyEnumerable<T> : IEnumerable<T>
{
    private readonly object _lock = new object();
    private List<T> _data;

    public MyEnumerable(List<T> data)
    {
        _data = data;
    }

    public IEnumerator<T> GetEnumerator()
    {
        return _data.GetEnumerator();
    }

    IEnumerator IEnumerable.GetEnumerator()
    {
        return GetEnumerator();
    }
}