diff --git a/dhp-workflows/dhp-aggregation/src/main/java/eu/dnetlib/dhp/collection/plugin/utils/XMLIterator.java b/dhp-workflows/dhp-aggregation/src/main/java/eu/dnetlib/dhp/collection/plugin/utils/XMLIterator.java
index ca351346c..7e5c5e3c3 100644
--- a/dhp-workflows/dhp-aggregation/src/main/java/eu/dnetlib/dhp/collection/plugin/utils/XMLIterator.java
+++ b/dhp-workflows/dhp-aggregation/src/main/java/eu/dnetlib/dhp/collection/plugin/utils/XMLIterator.java
@@ -70,10 +70,11 @@ public class XMLIterator implements Iterator<String> {
 		super();
 		this.element = element;
 		if (element.contains(",")) {
-			elements= Arrays.stream(element.split(","))
-					.filter(StringUtils::isNoneBlank)
-					.map(String::toLowerCase)
-					.collect(Collectors.toList());
+			elements = Arrays
+				.stream(element.split(","))
+				.filter(StringUtils::isNoneBlank)
+				.map(String::toLowerCase)
+				.collect(Collectors.toList());
 		}
 		this.inputStream = inputStream;
 		this.parser = getParser();
@@ -155,16 +156,16 @@ public class XMLIterator implements Iterator<String> {
 		XMLEvent peek = parser.peek();
 		if (peek != null && peek.isStartElement()) {
 			String name = peek.asStartElement().getName().getLocalPart();
-			if( isCheckTag(name))
-				return  peek;
+			if (isCheckTag(name))
+				return peek;
 		}
 
 		while (parser.hasNext()) {
-			XMLEvent event= parser.nextEvent();
+			XMLEvent event = parser.nextEvent();
 			if (event != null && event.isStartElement()) {
 				String name = event.asStartElement().getName().getLocalPart();
-				if( isCheckTag(name))
-					return  event;
+				if (isCheckTag(name))
+					return event;
 			}
 		}
 		return null;
@@ -181,12 +182,13 @@ public class XMLIterator implements Iterator<String> {
 	}
 
 	private boolean isCheckTag(final String tagName) {
-		if (elements!= null) {
-			final String found =elements.stream()
-					.filter(e -> e.equalsIgnoreCase(tagName))
-					.findFirst()
-					.orElse(null);
-			if (found!= null)
+		if (elements != null) {
+			final String found = elements
+				.stream()
+				.filter(e -> e.equalsIgnoreCase(tagName))
+				.findFirst()
+				.orElse(null);
+			if (found != null)
 				return true;
 		} else {
 			if (element.equalsIgnoreCase(tagName)) {
diff --git a/dhp-workflows/dhp-aggregation/src/test/java/eu/dnetlib/dhp/collection/plugin/file/FileGZipMultipleNodeTest.java b/dhp-workflows/dhp-aggregation/src/test/java/eu/dnetlib/dhp/collection/plugin/file/FileGZipMultipleNodeTest.java
index 2ed199156..2b5e90ab2 100644
--- a/dhp-workflows/dhp-aggregation/src/test/java/eu/dnetlib/dhp/collection/plugin/file/FileGZipMultipleNodeTest.java
+++ b/dhp-workflows/dhp-aggregation/src/test/java/eu/dnetlib/dhp/collection/plugin/file/FileGZipMultipleNodeTest.java
@@ -1,9 +1,11 @@
+
 package eu.dnetlib.dhp.collection.plugin.file;
 
+import java.io.IOException;
+import java.util.HashMap;
+import java.util.Objects;
+import java.util.stream.Stream;
 
-import eu.dnetlib.dhp.collection.ApiDescriptor;
-import eu.dnetlib.dhp.common.aggregation.AggregatorReport;
-import eu.dnetlib.dhp.common.collection.CollectorException;
 import org.apache.hadoop.conf.Configuration;
 import org.apache.hadoop.fs.FileSystem;
 import org.junit.jupiter.api.*;
@@ -12,52 +14,51 @@ import org.mockito.junit.jupiter.MockitoExtension;
 import org.slf4j.Logger;
 import org.slf4j.LoggerFactory;
 
-import java.io.IOException;
-import java.util.HashMap;
-import java.util.Objects;
-import java.util.stream.Stream;
+import eu.dnetlib.dhp.collection.ApiDescriptor;
+import eu.dnetlib.dhp.common.aggregation.AggregatorReport;
+import eu.dnetlib.dhp.common.collection.CollectorException;
 
 @TestMethodOrder(MethodOrderer.OrderAnnotation.class)
 @ExtendWith(MockitoExtension.class)
 public class FileGZipMultipleNodeTest {
 
-    private static final Logger log = LoggerFactory.getLogger(FileGZipCollectorPluginTest.class);
+	private static final Logger log = LoggerFactory.getLogger(FileGZipCollectorPluginTest.class);
 
-    private final ApiDescriptor api = new ApiDescriptor();
+	private final ApiDescriptor api = new ApiDescriptor();
 
-    private FileGZipCollectorPlugin plugin;
+	private FileGZipCollectorPlugin plugin;
 
-    private static final String SPLIT_ON_ELEMENT = "incollection,article";
+	private static final String SPLIT_ON_ELEMENT = "incollection,article";
 
-    @BeforeEach
-    public void setUp() throws IOException {
+	@BeforeEach
+	public void setUp() throws IOException {
 
-        final String gzipFile = Objects
-                .requireNonNull(
-                        this
-                                .getClass()
-                                .getResource("/eu/dnetlib/dhp/collection/plugin/file/dblp.gz"))
-                .getFile();
+		final String gzipFile = Objects
+			.requireNonNull(
+				this
+					.getClass()
+					.getResource("/eu/dnetlib/dhp/collection/plugin/file/dblp.gz"))
+			.getFile();
 
-        api.setBaseUrl(gzipFile);
+		api.setBaseUrl(gzipFile);
 
-        HashMap<String, String> params = new HashMap<>();
-        params.put("splitOnElement", SPLIT_ON_ELEMENT);
+		HashMap<String, String> params = new HashMap<>();
+		params.put("splitOnElement", SPLIT_ON_ELEMENT);
 
-        api.setParams(params);
+		api.setParams(params);
 
-        FileSystem fs = FileSystem.get(new Configuration());
-        plugin = new FileGZipCollectorPlugin(fs);
-    }
+		FileSystem fs = FileSystem.get(new Configuration());
+		plugin = new FileGZipCollectorPlugin(fs);
+	}
 
-    @Test
-    void test() throws CollectorException {
+	@Test
+	void test() throws CollectorException {
 
-        final Stream<String> stream = plugin.collect(api, new AggregatorReport());
+		final Stream<String> stream = plugin.collect(api, new AggregatorReport());
 
-        stream.limit(10).forEach(s -> {
-            Assertions.assertTrue(s.length() > 0);
-            log.info(s);
-        });
-    }
+		stream.limit(10).forEach(s -> {
+			Assertions.assertTrue(s.length() > 0);
+			log.info(s);
+		});
+	}
 }