Ability to modify api

api/src/main/java/co/aikar/util/Counter.java

@@ -0,0 +1,38 @@
+package co.aikar.util;
+
+import com.google.common.collect.ForwardingMap;
+
+import java.util.HashMap;
+import java.util.Map;
+import org.jetbrains.annotations.NotNull;
+import org.jetbrains.annotations.Nullable;
+
+public class Counter <T> extends ForwardingMap<T, Long> {
+    private final Map<T, Long> counts = new HashMap<>();
+
+    public long decrement(@Nullable T key) {
+        return increment(key, -1);
+    }
+    public long increment(@Nullable T key) {
+        return increment(key, 1);
+    }
+    public long decrement(@Nullable T key, long amount) {
+        return decrement(key, -amount);
+    }
+    public long increment(@Nullable T key, long amount) {
+        Long count = this.getCount(key);
+        count += amount;
+        this.counts.put(key, count);
+        return count;
+    }
+
+    public long getCount(@Nullable T key) {
+        return this.counts.getOrDefault(key, 0L);
+    }
+
+    @NotNull
+    @Override
+    protected Map<T, Long> delegate() {
+        return this.counts;
+    }
+}