diff --git a/pdb-api/src/main/java/org/lucares/pdb/api/UniqueStringIntegerPairs.java b/pdb-api/src/main/java/org/lucares/pdb/api/UniqueStringIntegerPairs.java
index 007a514..3cd73e1 100644
--- a/pdb-api/src/main/java/org/lucares/pdb/api/UniqueStringIntegerPairs.java
+++ b/pdb-api/src/main/java/org/lucares/pdb/api/UniqueStringIntegerPairs.java
@@ -165,7 +165,7 @@ public class UniqueStringIntegerPairs {
         intToString.set(value, string);
     }
 
-    void put(final String string, final int integer) {
+    void putStringAndInteger(final String string, final int integer) {
 
         if (stringToInt.containsKey(string) || (intToString.size() > integer && intToString.get(integer) != null)) {
             throw new IllegalArgumentException("Unique key constraint violation for (" + string + ", " + integer + ")");
@@ -197,7 +197,7 @@ public class UniqueStringIntegerPairs {
             synchronized (stringToInt) {
                 if (!stringToInt.containsKey(string)) {
                     final Integer second = mappingFunction.apply(string);
-                    put(string, second);
+                    putStringAndInteger(string, second);
                 }
             }
         }
@@ -231,7 +231,8 @@ public class UniqueStringIntegerPairs {
                     }
 
                     final Integer integer = intToString.size();
-                    put(normalizedString, integer); // adds the normalized String to stringToInt and bytesToInt
+                    putStringAndInteger(normalizedString, integer); // adds the normalized String to stringToInt and
+                                                                    // bytesToInt
                     bytesToInt.put(byteArray, integer); // also add the original String to bytesToInt, because it is
                                                         // used as cache
                 }
diff --git a/pdb-api/src/test/java/org/lucares/pdb/api/UniqueStringIntegerPairsTest.java b/pdb-api/src/test/java/org/lucares/pdb/api/UniqueStringIntegerPairsTest.java
index cd60616..1e8dd3d 100644
--- a/pdb-api/src/test/java/org/lucares/pdb/api/UniqueStringIntegerPairsTest.java
+++ b/pdb-api/src/test/java/org/lucares/pdb/api/UniqueStringIntegerPairsTest.java
@@ -5,9 +5,9 @@ import java.nio.file.Files;
 import java.nio.file.Path;
 
 import org.junit.jupiter.api.AfterEach;
+import org.junit.jupiter.api.Assertions;
 import org.junit.jupiter.api.BeforeEach;
 import org.junit.jupiter.api.Test;
-import org.junit.jupiter.api.Assertions;
 import org.lucares.utils.file.FileUtils;
 
 public class UniqueStringIntegerPairsTest {
@@ -33,7 +33,7 @@ public class UniqueStringIntegerPairsTest {
         {
             final UniqueStringIntegerPairs usip = new UniqueStringIntegerPairs(database);
 
-            usip.put(first, second);
+            usip.putStringAndInteger(first, second);
             Assertions.assertEquals(second, usip.get(first));
             Assertions.assertEquals(first, usip.getKey(second));
         }
@@ -53,11 +53,11 @@ public class UniqueStringIntegerPairsTest {
         final Integer second = 1;
 
         final UniqueStringIntegerPairs usip = new UniqueStringIntegerPairs(database);
-        usip.put(first, second);
+        usip.putStringAndInteger(first, second);
         try {
             // cannot add another pair with the first key
             final int another = second + 1;
-            usip.put(first, another);
+            usip.putStringAndInteger(first, another);
             Assertions.fail("expected an IllegalArgumentException");
         } catch (final IllegalArgumentException e) {
             // expected
@@ -66,7 +66,7 @@ public class UniqueStringIntegerPairsTest {
         try {
             // cannot add another pair with the same second value
             final String another = first + 1;
-            usip.put(another, second);
+            usip.putStringAndInteger(another, second);
             Assertions.fail("expected an IllegalArgumentException");
         } catch (final IllegalArgumentException e) {
             // expected