Add extra methods to EntityRequestBuilders

Prevents developer from having to manually overwrite:
- DriveItemRequestBuilder
- IDriveItemReqestBuilder
- ThumbnailSetRequestBuilder
- IThumbnailSetRequestBuilder

Author: Caitlin Bales (MSFT)

Templates/Android/BaseModel.template.tt

@@ -2,6 +2,7 @@
 <#@ template debug="true" hostspecific="true" language="C#" #>
 <#@ output extension="\\" #>
 <#
+
     CustomT4Host host          = (CustomT4Host) Host;
     var model                  = host.CurrentModel;
     CodeWriterAndroid writer   = (CodeWriterAndroid) host.CodeWriter;
@@ -799,4 +800,12 @@ public {1} {2}{3}{4} {{";
         return
 @"// **NOTE** This file was generated by a tool and any changes will be overwritten.";
     }
+
+	public string AddCustomCode(string className) {
+		CustomMethods customMethods = new CustomMethods();
+		var type = customMethods.GetType();
+		var property = type.GetFields().Where(x => x.Name == className).FirstOrDefault();
+
+		return property != null ? property.GetValue(customMethods).ToString() : string.Empty;
+	}
 #>

Templates/Android/extensions/EntityRequestBuilder.java.tt

@@ -18,4 +18,6 @@
     public <#=TypeRequestBuilder(c)#>(final String requestUrl, final <#=IBaseClientType()#> client, final java.util.List<Option> requestOptions) {
         super(requestUrl, client, requestOptions);
     }
+
+<#=AddCustomCode(TypeRequestBuilder(c))#>
 }

Templates/Android/extensions/IEntityRequestBuilder.java.tt

@@ -8,4 +8,5 @@
 
 <#=CreateInterfaceDef(ITypeRequestBuilder(c), IBaseTypeRequestBuilder(c))#>
 
+<#=AddCustomCode(ITypeRequestBuilder(c))#>
 }

src/GraphODataTemplateWriter/CodeHelpers/Android/CustomMethods.cs

@@ -0,0 +1,39 @@
+using System;
+using System.Collections.Generic;
+using System.Linq;
+using System.Text;
+using System.Threading.Tasks;
+
+namespace Microsoft.Graph.ODataTemplateWriter.CodeHelpers.Android
+{
+    public class CustomMethods
+    {
+        public const string DriveItemRequestBuilder = 
+            "    @Override\r\n" +
+            "    public IDriveItemRequestBuilder getItemWithPath(final String path) {\r\n" +
+            "        return new DriveItemRequestBuilder(getRequestUrl() + \":/\" + path + \":\", getClient(), null);\r\n" +
+            "    }";
+
+        public const string IDriveItemRequestBuilder =
+            "    /**\r\n" +
+            "     * Gets the item request builder for the specified item path\r\n" +
+            "     * @param path The path to the item\r\n" +
+            "     * @return The request builder for the specified item\r\n" +
+            "     */\r\n" +
+            "    IDriveItemRequestBuilder getItemWithPath(final String path);";
+
+        public const string IThumbnailSetRequestBuilder =
+            "    /**\r\n" +
+            "     * Gets a request for a thumbnail of a specific size\r\n" +
+            "     * @param size The size to request (typically: small, medium, large)\r\n" +
+            "     * @return The request builder for that thumbnail size\r\n" +
+            "     */\r\n" +
+            "    IThumbnailRequestBuilder getThumbnailSize(final String size);";
+
+        public const string ThumbnailSetRequestBuilder =
+            "    @Override\r\n" +
+            "    public IThumbnailRequestBuilder getThumbnailSize(final String size) {\r\n" +
+            "        return new ThumbnailRequestBuilder(getRequestUrlWithAdditionalSegment(size), getClient(), /* options */ null);\r\n" +
+            "    }";
+    }
+}