Update error for custom requests

Author: Caitlin Bales (MSFT)

src/main/java/com/microsoft/graph/http/BaseRequest.java

@@ -153,8 +153,13 @@ public URL getRequestUrl() {
         try {
             return new URL(uriBuilder.build().toString());
         } catch (final MalformedURLException e) {
-            throw new ClientException("Invalid URL: " + uriBuilder.toString(), e);
+        	if (this instanceof CustomRequest) {
+        		this.getClient().getLogger().logError("Invalid custom URL: " + uriBuilder.toString(), e);
+        	} else {
+        		throw new ClientException("Invalid URL: " + uriBuilder.toString(), e);
+        	}
         }
+		return null;
     }
 
     private String addFunctionParameters() {

src/main/java/com/microsoft/graph/requests/extensions/CustomRequestBuilder.java

@@ -8,6 +8,11 @@
 import com.microsoft.graph.models.extensions.GraphServiceClient;
 import com.microsoft.graph.options.Option;
 
+/**
+ * The class for the CustomRequestBuilder
+ *
+ * @throws ClientException If the provided URL is malformed, the client exception will contain a MalformedURLException
+ */
 public class CustomRequestBuilder extends BaseRequestBuilder {
 	public final Class responseType;