Adding files were forgotten in last commit

Author: ldecheverz-split

client/src/main/java/io/split/client/FactoryInstantiationsService.java

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+package io.split.client;
+
+import com.google.common.collect.ConcurrentHashMultiset;
+import com.google.common.collect.Multiset;
+import org.slf4j.Logger;
+import org.slf4j.LoggerFactory;
+
+public class FactoryInstantiationsService {
+
+    private static final Logger _log = LoggerFactory.getLogger(FactoryInstantiationsService.class);
+    private static volatile FactoryInstantiationsService _factoryInstantiationsService;
+    private static final Multiset<String> USED_API_TOKENS = ConcurrentHashMultiset.create();
+
+
+    private FactoryInstantiationsService() {}
+
+    public static FactoryInstantiationsService getFactoryInstantiationsServiceInstance() {
+        if(_factoryInstantiationsService == null) {
+            synchronized (FactoryInstantiationsService.class) {
+                if (_factoryInstantiationsService == null) {
+                    _factoryInstantiationsService = new FactoryInstantiationsService();
+                }
+            }
+        }
+
+        return _factoryInstantiationsService;
+    }
+
+    public void addToken(String apiToken) {
+        String message;
+        if (USED_API_TOKENS.contains(apiToken)) {
+            message = String.format("factory instantiation: You already have %s with this API Key. " +
+                            "We recommend keeping only one instance of the factory at all times (Singleton pattern) and reusing " +
+                            "it throughout your application.",
+                    USED_API_TOKENS.count(apiToken) == 1 ? "1 factory" : String.format("%s factories", USED_API_TOKENS.count(apiToken)));
+            _log.warn(message);
+        } else if (!USED_API_TOKENS.isEmpty()) {
+             message = "factory instantiation: You already have an instance of the Split factory. " +
+                    "Make sure you definitely want this additional instance. We recommend keeping only one instance of " +
+                    "the factory at all times (Singleton pattern) and reusing it throughout your application.“";
+            _log.warn(message);
+        }
+        USED_API_TOKENS.add(apiToken);
+    }
+
+    public void removeToken(String apiToken) {
+        USED_API_TOKENS.remove(apiToken);
+    }
+
+    /**
+     * Just for test
+     * @param apiToken
+     * @return
+     */
+    public boolean isTokenPresent(String apiToken){
+        return USED_API_TOKENS.contains(apiToken);
+    }
+}

client/src/test/java/io/split/client/FactoryInstantiationsServiceTest.java

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+package io.split.client;
+
+import junit.framework.TestCase;
+
+public class FactoryInstantiationsServiceTest extends TestCase {
+
+
+}