Replace EMPTY_MAP with type safe Collections.emptyMap()

Author: claussni

src/main/java/de/slub/urn/RQF_RFC8141.java

@@ -22,8 +22,6 @@
 import java.util.List;
 import java.util.Map;
 
-import static java.util.Collections.EMPTY_MAP;
-
 /**
  * Class for representing and parsing optional resolution, query and fragment components
  * and making them accessible via unmodifiable maps.
@@ -37,7 +35,7 @@ public final class RQF_RFC8141 {
      *
      * @see <a href="https://en.wikipedia.org/wiki/Null_object_pattern">Null object pattern</a>
      */
-    public static final RQF_RFC8141 NULL = new RQF_RFC8141(EMPTY_MAP, EMPTY_MAP, "");
+    public static final RQF_RFC8141 NULL = new RQF_RFC8141(Collections.emptyMap(), Collections.emptyMap(), "");
 
     private final Map<String, String> resolutionParameters;
     private final Map<String, String> queryParameters;

src/test/java/de/slub/urn/RQFRFC8141Test.java

@@ -52,17 +52,17 @@ public void NULL_object_is_not_equal_to_null() {
 
     @Test(expected = IllegalArgumentException.class)
     public void Passing_null_as_resolutionParameterMap_throws_exception() {
-        new RQF_RFC8141(null, Collections.EMPTY_MAP, "");
+        new RQF_RFC8141(null, Collections.emptyMap(), "");
     }
 
     @Test(expected = IllegalArgumentException.class)
     public void Passing_null_as_queryParameterMap_throws_exception() {
-        new RQF_RFC8141(Collections.EMPTY_MAP, null, "");
+        new RQF_RFC8141(Collections.emptyMap(), null, "");
     }
 
     @Test(expected = IllegalArgumentException.class)
     public void Passing_null_as_fragment_throws_exception() {
-        new RQF_RFC8141(Collections.EMPTY_MAP, Collections.EMPTY_MAP, null);
+        new RQF_RFC8141(Collections.emptyMap(), Collections.emptyMap(), null);
     }