HttpClient + PATCH support

From - http://compiledexperience.com/blog/posts/patch-support-in-httpclient/

public static class HttpClientExtensions
{
    public async static Task<HttpResponseMessage> PatchAsync(this HttpClient client, string requestUri, HttpContent content)
    {
        var method = new HttpMethod("PATCH");  

        var request = new HttpRequestMessage(method, requestUri)
        {
            Content = content
        };  

        return await client.SendAsync(request);
    }  

    public async static Task<HttpResponseMessage> PatchAsync(this HttpClient client, Uri requestUri, HttpContent content)
    {
        var method = new HttpMethod("PATCH");  

        var request = new HttpRequestMessage(method, requestUri)
        {
            Content = content
        };  

        return await client.SendAsync(request);
    }  

    public async static Task<HttpResponseMessage> PatchAsync(this HttpClient client, string requestUri, HttpContent content, CancellationToken cancellationToken)
    {
        var method = new HttpMethod("PATCH");  

        var request = new HttpRequestMessage(method, requestUri)
        {
            Content = content
        };  

        return await client.SendAsync(request, cancellationToken);
    }  

    public async static Task<HttpResponseMessage> PatchAsync(this HttpClient client, Uri requestUri, HttpContent content, CancellationToken cancellationToken)
    {
        var method = new HttpMethod("PATCH");  

        var request = new HttpRequestMessage(method, requestUri)
        {
            Content = content
        };  

        return await client.SendAsync(request, cancellationToken);
    }
}