List extensions in c#

Extensions.cs

using System.Linq;
using UnityEngine;
using System;
using System.Collections.Generic;
using Debug = UnityEngine.Debug;
using Object = UnityEngine.Object;
using Random = UnityEngine.Random;

public static class Extensions
{
    public static T PopFirst<T>(this IList<T> t)
    {
        T element = t[0];
        t.RemoveAt(0);
        return element;       
    }

    public static void PushFirst<T>(this IList<T> t, T element)
    {
        t.Insert(0, element);
    }

    public static T PopLast<T>(this IList<T> t)
    {
        T element = t[t.Count - 1];
        t.RemoveAt(t.Count - 1);
        return element;
    }

    public static void PushLast<T>(this IList<T> t, T element)
    {
        t.Add(element);
    }


    public static T PickRandom<T>(this IEnumerable<T> ie)
    {
        List<T> t = ie as List<T> ?? ie.ToList();
        if(t.Count == 0)
		{
			Debug.LogError("Range is zero!");
			return default(T);
		}
		return t[Random.Range(0, t.Count)];
	}
	}