add Sparse2DLongArray

primitiveCollections/src/main/java/org/lucares/collections/TripleLongConsumer.java

@@ -0,0 +1,15 @@
+package org.lucares.collections;
+
+/**
+ * Consumer for iterating over {@link Sparse2DLongArray}s.
+ */
+public interface TripleLongConsumer {
+	
+	/**
+	 * Performs this operation on the given arguments
+	 * @param x the index in the x-dimension
+	 * @param y the index in the y-dimension
+	 * @param value the value at {@code x}×{@code y}
+	 */
+	public void apply(long x, long y, long value);
+}