Filtering out values from a C# Generic Dictionary

IDictionary+WhereToDictionary.cs

using System.Collections.Generic;

namespace System.Linq
{
    /// <summary>
    /// Filtering out values from a C# Generic Dictionary
    /// </summary>
    /// <seealso cref="https://stackoverflow.com/questions/2131648/filtering-out-values-from-a-c-sharp-generic-dictionary"/>
    public static class IDictionary_WhereToDictionary
    {
        /// <summary>
        /// If you don't care about creating a new dictionary with the desired items and throwing away the old one, simply try:
        /// </summary>
        /// <param name="this"></param>
        /// <param name="predicate"></param>
        /// <typeparam name="TKey"></typeparam>
        /// <typeparam name="TValue"></typeparam>
        /// <returns></returns>
        public static Dictionary<TKey, TValue> WhereToDictionary<TKey, TValue>(
            this IDictionary<TKey, TValue> @this,
            Func<KeyValuePair<TKey, TValue>, bool> predicate)
            => @this.Where(predicate).ToDictionary(
                kvp => kvp.Key,
                kvp => kvp.Value);


        /// <summary>
        /// If you can't create a new dictionary and need to alter the old one for some reason (like when it's externally referenced and you can't update all the references:
        /// </summary>
        /// <param name="this"></param>
        /// <param name="predicate"></param>
        /// <typeparam name="TKey"></typeparam>
        /// <typeparam name="TValue"></typeparam>
        public static void WhereMutable<TKey, TValue>(
            this IDictionary<TKey, TValue> @this,
            Func<KeyValuePair<TKey, TValue>, bool> predicate)
        {
            foreach (var item in @this.Where(predicate).ToList())
                @this.Remove(item.Key);
        }
    }
}