Add Miscellaneous#getMapValue method

base/src/main/java/de/staropensource/sosengine/base/utility/Miscellaneous.java

@@ -22,6 +22,10 @@ package de.staropensource.sosengine.base.utility;
 import org.jetbrains.annotations.NotNull;
 
 import java.lang.ref.WeakReference;
+import java.util.Map;
+import java.util.Objects;
+import java.util.Set;
+import java.util.stream.Collectors;
 
 /**
  * Contains smaller functions that don't fit into other utility classes.
@@ -76,4 +80,15 @@ public final class Miscellaneous {
         runnable.run();
         return System.currentTimeMillis() - initTime;
     }
+
+    /**
+     * Searches for a value in a {@link Map}.
+     *
+     * @param map   map to use
+     * @param value value to search for
+     * @since 1-alpha0
+     */
+    public static Set<?> getMapValue(Map<?, ?> map, Object value) {
+        return map.entrySet().stream().filter(entry -> Objects.equals(entry.getValue(), value)).map(Map.Entry::getKey).collect(Collectors.toSet());
+    }
 }