fix some unused imports and raw type usage

Author: davidmoten

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

@@ -27,7 +27,6 @@
 
 import com.microsoft.graph.concurrency.ICallback;
 import com.microsoft.graph.core.IBaseClient;
-import com.microsoft.graph.core.GraphErrorCodes;
 import com.microsoft.graph.options.FunctionOption;
 import com.microsoft.graph.options.QueryOption;
 import com.microsoft.graph.core.ClientException;
@@ -89,7 +88,7 @@ public abstract class BaseRequest implements IHttpRequest {
     /**
      * The class for the response
      */
-    private final Class responseClass;
+    private final Class<?> responseClass;
 
     /**
      * Value to pass to setUseCaches in connection
@@ -257,7 +256,7 @@ protected <T1, T2> void send(final HttpMethod method,
                                  final ICallback<T1> callback,
                                  final T2 serializedObject) {
         this.method = method;
-        client.getHttpProvider().send(this, callback, responseClass, serializedObject);
+        client.getHttpProvider().send(this, callback, (Class<T1>) responseClass, serializedObject);
     }
 
     /**
@@ -349,8 +348,7 @@ public IBaseClient getClient() {
      *
      * @return the response type
      */
-    @SuppressWarnings("unchecked")
-	public Class getResponseType() {
+	public Class<?> getResponseType() {
         return responseClass;
     }
 }

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

@@ -24,7 +24,6 @@
 
 import com.microsoft.graph.core.IBaseClient;
 import com.microsoft.graph.options.Option;
-import com.microsoft.graph.serializer.IJsonBackedObject;
 
 import java.util.ArrayList;
 import java.util.Collections;

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

@@ -90,7 +90,7 @@ protected InputStream send() throws ClientException {
     @SuppressWarnings("unchecked")
     protected void send(final byte[] fileContents, final ICallback<T> callback) {
         baseRequest.setHttpMethod(HttpMethod.PUT);
-        baseRequest.getClient().getHttpProvider().send(this, callback, baseRequest.getResponseType(), fileContents);
+        baseRequest.getClient().getHttpProvider().send(this, callback, (Class<T>) baseRequest.getResponseType(), fileContents);
     }
 
     /**

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

@@ -28,7 +28,6 @@
 import com.microsoft.graph.concurrency.IExecutors;
 import com.microsoft.graph.concurrency.IProgressCallback;
 import com.microsoft.graph.core.ClientException;
-import com.microsoft.graph.core.GraphErrorCodes;
 import com.microsoft.graph.logger.ILogger;
 import com.microsoft.graph.logger.LoggerLevel;
 import com.microsoft.graph.options.HeaderOption;
@@ -206,6 +205,7 @@ public <Result, Body, DeserializeType> Result send(final IHttpRequest request,
      * @return                  the result from the request
      * @throws ClientException an exception occurs if the request was unable to complete for any reason
      */
+    @SuppressWarnings("unchecked")
     private <Result, Body, DeserializeType> Result sendRequestInternal(final IHttpRequest request,
                                                                        final Class<Result> resultClass,
                                                                        final Body serializable,