Some C#--Language extensions

Extensions.cs

using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;

namespace Extensions
{
    public static class Extensions
    {
        public static void Times(this int t, Action<int> f)
        {
            for (int i = 0; i < t; i++)
            {
                f(i);
            }
        }

        public static void Times(this int t, Action f)
        {
            for (int i = 0; i < t; i++)
            {
                f();
            }
        }

        public static R CallConverted<T, R>(this object o, Func<T, R> f) where T : class
        {
            var converted = o as T;

            if (converted != null)
            {
                return f(converted);
            }
            else
            {
                return default(R);
            }
        }

        public static void CallConverted<T>(this object o, Action<T> f) where T : class
        {
            var converted = o as T;

            if (converted != null)
            {
                f(converted);
            }
        }

        public static TValue GetOrCreateValue<TKey, TValue>(this IDictionary<TKey, TValue> dict, TKey key, Func<TKey, TValue> createFn)
        {
            TValue value = default(TValue);

            if (dict.TryGetValue(key, out value))
            {
                return value;
            }
            else
            {
                value = createFn(key);
                dict[key] = value;
                return value;
            }
        }

        public static bool NullAndConditionCheck<T>(T t, Func<T, bool> f) where T : class
        {
            if (t != null)
            {
                return f(t);
            }
            else
            {
                return false;
            }
        }

        public static T GetExistingOrCreateNew<T>(T t, Func<T> f) where T : class
        {
            if (t != null)
                return t;

            else return f();
        }

        public static void OpenPathForReading(this string s, Action<System.IO.StreamReader> f)
        {
            using (var inputStream = new System.IO.StreamReader(s))
            {
                f(inputStream);
            }
        }

        public static void OpenPathForWriting(this string s, Action<System.IO.StreamWriter> f)
        {
            using (var outputStream = new System.IO.StreamWriter(s))
            {
                f(outputStream);
            }
        }


    }
}