Add getSources and getDestinations

src/main/java/org/warp/commonutils/type/Association.java

@@ -1,5 +1,6 @@
 package org.warp.commonutils.type;
 
+import it.unimi.dsi.fastutil.objects.ObjectSet;
 import java.util.Optional;
 import java.util.Set;
 
@@ -101,6 +102,18 @@ public interface Association<T, U> {
 	 */
 	int size();
 
+	/**
+	 * Get all the sources
+	 * @return Set of sources
+	 */
+	ObjectSet<T> getSources();
+
+	/**
+	 * Get all the destinations
+	 * @return Set of destinations
+	 */
+	ObjectSet<U> getDestinations();
+
 	static <T, U> Association<T, U> synchronize(Association<T, U> association) {
 		return new SynchronizedAssociation(association);
 	}

src/main/java/org/warp/commonutils/type/BiAssociation.java

@@ -1,5 +1,6 @@
 package org.warp.commonutils.type;
 
+import it.unimi.dsi.fastutil.objects.ObjectSet;
 import java.util.Optional;
 
 /**
@@ -100,6 +101,18 @@ public interface BiAssociation<T, U> {
 	 */
 	int size();
 
+	/**
+	 * Get all the sources
+	 * @return Set of sources
+	 */
+	ObjectSet<T> getSources();
+
+	/**
+	 * Get all the destinations
+	 * @return Set of destinations
+	 */
+	ObjectSet<U> getDestinations();
+
 	static <T, U> BiAssociation<T, U> synchronize(BiAssociation<T, U> association) {
 		return new SynchronizedBiAssociation(association);
 	}

src/main/java/org/warp/commonutils/type/HashAssociation.java

@@ -2,6 +2,7 @@ package org.warp.commonutils.type;
 
 import it.unimi.dsi.fastutil.objects.Object2ObjectOpenHashMap;
 import it.unimi.dsi.fastutil.objects.ObjectOpenHashSet;
+import it.unimi.dsi.fastutil.objects.ObjectSet;
 import java.util.Objects;
 import java.util.Optional;
 import java.util.Set;
@@ -156,6 +157,16 @@ public class HashAssociation<T, U> implements Association<T, U> {
 		return inverseAssociations.size();
 	}
 
+	@Override
+	public ObjectSet<T> getSources() {
+		return associations.clone().keySet();
+	}
+
+	@Override
+	public ObjectSet<U> getDestinations() {
+		return inverseAssociations.clone().keySet();
+	}
+
 	@SuppressWarnings("MethodDoesntCallSuperMethod")
 	@Override
 	public HashAssociation<T, U> clone() {

src/main/java/org/warp/commonutils/type/HashBiAssociation.java

@@ -1,6 +1,7 @@
 package org.warp.commonutils.type;
 
 import it.unimi.dsi.fastutil.objects.Object2ObjectOpenHashMap;
+import it.unimi.dsi.fastutil.objects.ObjectSet;
 import java.util.Objects;
 import java.util.Optional;
 
@@ -134,6 +135,16 @@ public class HashBiAssociation<T, U> implements BiAssociation<T, U> {
 		return inverseAssociations.size();
 	}
 
+	@Override
+	public ObjectSet<T> getSources() {
+		return associations.clone().keySet();
+	}
+
+	@Override
+	public ObjectSet<U> getDestinations() {
+		return inverseAssociations.clone().keySet();
+	}
+
 	@SuppressWarnings("MethodDoesntCallSuperMethod")
 	@Override
 	public HashBiAssociation<T, U> clone() {

src/main/java/org/warp/commonutils/type/SynchronizedAssociation.java

@@ -1,5 +1,6 @@
 package org.warp.commonutils.type;
 
+import it.unimi.dsi.fastutil.objects.ObjectSet;
 import java.util.Optional;
 import java.util.Set;
 
@@ -94,4 +95,18 @@ public final class SynchronizedAssociation<T, U> implements Association<T, U> {
 			return association.size();
 		}
 	}
+
+	@Override
+	public ObjectSet<T> getSources() {
+		synchronized (lock) {
+			return association.getSources();
+		}
+	}
+
+	@Override
+	public ObjectSet<U> getDestinations() {
+		synchronized (lock) {
+			return association.getDestinations();
+		}
+	}
 }

src/main/java/org/warp/commonutils/type/SynchronizedBiAssociation.java

@@ -1,5 +1,6 @@
 package org.warp.commonutils.type;
 
+import it.unimi.dsi.fastutil.objects.ObjectSet;
 import java.util.Optional;
 
 public final class SynchronizedBiAssociation<T, U> implements BiAssociation<T, U> {
@@ -93,4 +94,18 @@ public final class SynchronizedBiAssociation<T, U> implements BiAssociation<T, U
 			return association.size();
 		}
 	}
+
+	@Override
+	public ObjectSet<T> getSources() {
+		synchronized (lock) {
+			return association.getSources();
+		}
+	}
+
+	@Override
+	public ObjectSet<U> getDestinations() {
+		synchronized (lock) {
+			return association.getDestinations();
+		}
+	}
 }