improves WeightedStats API

Signed-off-by: Oleh Dokuka <shadowgun@i.ua>

Author: OlegDokuka

rsocket-core/src/main/java/io/rsocket/loadbalance/BaseWeightedStats.java

@@ -81,7 +81,7 @@ public int pending() {
   }
 
   @Override
-  public double availability() {
+  public double weightedAvailability() {
     if (Clock.now() - stamp > tau) {
       updateAvailability(1.0);
     }

rsocket-core/src/main/java/io/rsocket/loadbalance/WeightedLoadbalanceStrategy.java

@@ -159,7 +159,7 @@ private static double algorithmicWeight(
       latency *= calculateFactor(latency, high, bandWidth);
     }
 
-    return (rSocket.availability() * weightedStats.availability())
+    return (rSocket.availability() * weightedStats.weightedAvailability())
         / (1.0d + latency * (pending + 1));
   }
 

rsocket-core/src/main/java/io/rsocket/loadbalance/WeightedStats.java

@@ -1,13 +1,11 @@
 package io.rsocket.loadbalance;
 
-import io.rsocket.Availability;
-
 /**
  * Representation of stats used by the {@link WeightedLoadbalanceStrategy}
  *
  * @since 1.1
  */
-public interface WeightedStats extends Availability {
+public interface WeightedStats {
 
   double higherQuantileLatency();
 
@@ -16,4 +14,6 @@ public interface WeightedStats extends Availability {
   int pending();
 
   double predictedLatency();
+
+  double weightedAvailability();
 }