Sanity check to ensure connection is closed

Also added docs to ensure clients call `close()`, which they really ought to have been doing already given the name "iterator".

Author: rjrudin

marklogic-client-api/src/main/java/com/marklogic/client/eval/EvalResultIterator.java

@@ -6,15 +6,23 @@
 import java.io.Closeable;
 import java.util.Iterator;
 
-/** An Iterator to walk through all results returned from calls to
+/**
+ * An Iterator to walk through all results returned from calls to
  * {@link ServerEvaluationCall#eval()}.
  */
 public interface EvalResultIterator extends Iterable<EvalResult>, Iterator<EvalResult>, Closeable {
-  @Override
-  Iterator<EvalResult> iterator();
-  @Override
-  boolean hasNext();
-  @Override
-  EvalResult next();
-  void close();
+	@Override
+	Iterator<EvalResult> iterator();
+
+	@Override
+	boolean hasNext();
+
+	@Override
+	EvalResult next();
+
+	/**
+	 * As of 7.1.0, this must be called to ensure that the response is closed, as results are now
+	 * streamed from MarkLogic instead of being read entirely into memory first.
+	 */
+	void close();
 }

marklogic-client-api/src/main/java/com/marklogic/client/impl/OkHttpServices.java

@@ -3856,7 +3856,17 @@ private <U extends OkHttpResultIterator> U evalAndStreamResults(RequestLogger re
 		try {
 			MultipartReader reader = new MultipartReader(response.body());
 			PartIterator partIterator = new PartIterator(reader);
-			return (U) new DefaultOkHttpResultIterator(reqlog, partIterator, response);
+			return (U) new DefaultOkHttpResultIterator(reqlog, partIterator, () -> {
+				// Looking at OkHttp source code, it does not appear necessary to call close on the reader; it appears
+				// sufficient to only call it on the response. But doing both in case this behavior changes in a future
+				// OkHttp release.
+				try {
+					reader.close();
+				} catch (IOException e) {
+					// Ignore, the next call should close everything properly.
+				}
+				response.close();
+			});
 		} catch (IOException e) {
 			throw new MarkLogicIOException(e);
 		}