Start porting request templates (etc) from HTTPlease

#166

src/KubeClient/Http/FactoryExtensions.cs

@@ -0,0 +1,35 @@
+using System;
+
+namespace KubeClient.Http
+{
+    /// <summary>
+    ///		Extension methods for <see cref="HttpRequestFactory"/>.
+    /// </summary>
+    public static class FactoryExtensions
+    {
+        /// <summary>
+        ///		Create a new HTTP request with the specified request URI.
+        /// </summary>
+        /// <param name="requestFactory">
+        ///		The HTTP request factory.
+        /// </param>
+        /// <param name="requestUri">
+        ///		The request URI (can be relative or absolute).
+        /// </param>
+        /// <returns>
+        ///		The new <see cref="HttpRequest"/>.
+        /// </returns>
+        public static HttpRequest Create(this HttpRequestFactory requestFactory, string requestUri)
+        {
+            if (requestFactory == null)
+                throw new ArgumentNullException(nameof(requestFactory));
+
+            if (String.IsNullOrWhiteSpace(requestUri))
+                throw new ArgumentException("Argument cannot be null, empty, or composed entirely of whitespace: 'requestUri'.", nameof(requestUri));
+
+            return requestFactory.Create(
+                new Uri(requestUri, UriKind.RelativeOrAbsolute)
+            );
+        }
+    }
+}