diff --git a/src/main/java/eu/dnetlib/validator2/validation/guideline/ElementSpecCompiler.java b/src/main/java/eu/dnetlib/validator2/validation/guideline/ElementSpecCompiler.java
index 9a141dc..e2a1f62 100644
--- a/src/main/java/eu/dnetlib/validator2/validation/guideline/ElementSpecCompiler.java
+++ b/src/main/java/eu/dnetlib/validator2/validation/guideline/ElementSpecCompiler.java
@@ -21,7 +21,6 @@ import java.util.function.Function;
 import java.util.function.Predicate;
 import java.util.function.Supplier;
 import java.util.stream.Collectors;
-import java.util.stream.Stream;
 
 class ElementSpecCompiler {
 
@@ -122,11 +121,11 @@ class ElementSpecCompiler {
     }
 
     static final String mergeNodeNames(String... names) {
-        return Stream.of(names).collect(Collectors.joining("/"));
+        return String.join("/", names);
     }
 
 
-    // Heuristic for avoiding to create rules for checking the allowed values, when all values are allowed.
+    // Heuristic for avoiding creating rules for checking the allowed values, when all values are allowed.
     private static boolean allowsAllValues(Predicate<String> allowedValuesPredicate) {
         return (allowedValuesPredicate == null || // null value will never occur through our Builders class.
                 allowedValuesPredicate == Builders.ALLOW_ALL_VALUES
diff --git a/src/main/java/eu/dnetlib/validator2/validation/guideline/openaire/LiteratureGuidelinesV4Profile.java b/src/main/java/eu/dnetlib/validator2/validation/guideline/openaire/LiteratureGuidelinesV4Profile.java
index ab91291..8ec4b23 100644
--- a/src/main/java/eu/dnetlib/validator2/validation/guideline/openaire/LiteratureGuidelinesV4Profile.java
+++ b/src/main/java/eu/dnetlib/validator2/validation/guideline/openaire/LiteratureGuidelinesV4Profile.java
@@ -218,7 +218,7 @@ public final class LiteratureGuidelinesV4Profile extends AbstractOpenAireProfile
     Date encoding "YYYY-MM-DD" is referred as best practice. Should introduce in allowed values?
     */
     //TODO: Implement proper applicability rule
-    //LEONIDAS: The withMandatoryAttribute fails whe another date element eg. for Publication Date exists
+    //LEONIDAS: The withMandatoryAttribute fails when another date element eg. for Publication Date exists
     private static final ElementSpec EMBARGO_PERIOD_DATE_SPEC = Builders.
             forMandatoryIfApplicableElement("datacite:date", TWO, applicabilityRuleForEmbargoPeriodDate()).
             withMandatoryAttribute("dateType", EMBARGO_DATE_TYPES).
diff --git a/src/main/java/eu/dnetlib/validator2/validation/guideline/openaire/R1_01M_LIT.java b/src/main/java/eu/dnetlib/validator2/validation/guideline/openaire/R1_01M_LIT.java
index 262da75..bd8d703 100644
--- a/src/main/java/eu/dnetlib/validator2/validation/guideline/openaire/R1_01M_LIT.java
+++ b/src/main/java/eu/dnetlib/validator2/validation/guideline/openaire/R1_01M_LIT.java
@@ -5,7 +5,6 @@ import eu.dnetlib.validator2.validation.guideline.ElementSpec;
 import eu.dnetlib.validator2.validation.guideline.Guideline;
 import eu.dnetlib.validator2.validation.guideline.SyntheticGuideline;
 import eu.dnetlib.validator2.validation.utils.MediaTypesValuePredicate;
-import eu.dnetlib.validator2.validation.utils.RegexValuePredicate;
 import org.w3c.dom.Document;
 
 import java.util.*;
@@ -13,7 +12,6 @@ import java.util.stream.Collectors;
 
 import static eu.dnetlib.validator2.validation.guideline.Cardinality.ONE;
 import static eu.dnetlib.validator2.validation.guideline.Cardinality.ONE_TO_N;
-import static eu.dnetlib.validator2.validation.utils.SupportedRegExs.COMPILED_BCP47_LANG_TAGS_REG_EX;
 
 public final class R1_01M_LIT extends AbstractOpenAireProfile {
 
diff --git a/src/test/java/eu/dnetlib/validator2/engine/Test.java b/src/test/java/eu/dnetlib/validator2/engine/Test.java
index acb5b1f..15495e9 100644
--- a/src/test/java/eu/dnetlib/validator2/engine/Test.java
+++ b/src/test/java/eu/dnetlib/validator2/engine/Test.java
@@ -3,6 +3,7 @@ package eu.dnetlib.validator2.engine;
 import eu.dnetlib.validator2.validation.XMLApplicationProfile;
 import eu.dnetlib.validator2.validation.guideline.Guideline;
 import eu.dnetlib.validator2.validation.guideline.openaire.LiteratureGuidelinesV3Profile;
+import eu.dnetlib.validator2.validation.utils.TestUtils;
 import org.slf4j.LoggerFactory;
 import org.w3c.dom.Document;
 
diff --git a/src/test/java/eu/dnetlib/validator2/engine/Test_FAIR.java b/src/test/java/eu/dnetlib/validator2/engine/Test_FAIR.java
index 9c9302a..ac731d8 100644
--- a/src/test/java/eu/dnetlib/validator2/engine/Test_FAIR.java
+++ b/src/test/java/eu/dnetlib/validator2/engine/Test_FAIR.java
@@ -3,6 +3,7 @@ package eu.dnetlib.validator2.engine;
 import eu.dnetlib.validator2.validation.XMLApplicationProfile;
 import eu.dnetlib.validator2.validation.guideline.Guideline;
 import eu.dnetlib.validator2.validation.guideline.openaire.FAIR_Data_GuidelinesProfile;
+import eu.dnetlib.validator2.validation.utils.TestUtils;
 import org.slf4j.LoggerFactory;
 import org.w3c.dom.Document;
 
diff --git a/src/test/java/eu/dnetlib/validator2/engine/Test_v2_data.java b/src/test/java/eu/dnetlib/validator2/engine/Test_v2_data.java
index 26c0745..77d3fe6 100644
--- a/src/test/java/eu/dnetlib/validator2/engine/Test_v2_data.java
+++ b/src/test/java/eu/dnetlib/validator2/engine/Test_v2_data.java
@@ -4,6 +4,7 @@ import eu.dnetlib.validator2.validation.XMLApplicationProfile;
 import eu.dnetlib.validator2.validation.guideline.Guideline;
 import eu.dnetlib.validator2.validation.guideline.openaire.AbstractOpenAireProfile;
 import eu.dnetlib.validator2.validation.guideline.openaire.DataArchiveGuidelinesV2Profile;
+import eu.dnetlib.validator2.validation.utils.TestUtils;
 import org.slf4j.LoggerFactory;
 import org.w3c.dom.Document;
 
diff --git a/src/test/java/eu/dnetlib/validator2/engine/Test_v4.java b/src/test/java/eu/dnetlib/validator2/engine/Test_v4.java
index 9cc04c1..116b6a1 100644
--- a/src/test/java/eu/dnetlib/validator2/engine/Test_v4.java
+++ b/src/test/java/eu/dnetlib/validator2/engine/Test_v4.java
@@ -4,6 +4,7 @@ import eu.dnetlib.validator2.validation.XMLApplicationProfile;
 import eu.dnetlib.validator2.validation.guideline.Guideline;
 import eu.dnetlib.validator2.validation.guideline.openaire.AbstractOpenAireProfile;
 import eu.dnetlib.validator2.validation.guideline.openaire.LiteratureGuidelinesV4Profile;
+import eu.dnetlib.validator2.validation.utils.TestUtils;
 import org.slf4j.LoggerFactory;
 import org.w3c.dom.Document;
 
@@ -18,7 +19,7 @@ public class Test_v4 {
 
     private static final org.slf4j.Logger logger = LoggerFactory.getLogger(Test_v4.class);
 
-    private static final String TEST_FILES_V4_DIR = TestUtils.TEST_FILES_BASE_DIR + "openaireguidelinesV4/";
+    public static final String TEST_FILES_V4_DIR = TestUtils.TEST_FILES_BASE_DIR + "openaireguidelinesV4/";
 
     private static final String[] FILES = new String[] {
 //            TEST_FILES_V4_DIR + "v4_literature_all_invalid_guidelines_record.xml",
@@ -27,6 +28,7 @@ public class Test_v4 {
             TEST_FILES_V4_DIR + "01_gv4.xml"
     };
 
+
     public static void main(String[] args) {
         // String xmlFile = args[0];
         AbstractOpenAireProfile profile = new LiteratureGuidelinesV4Profile();