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diff --git a/subprojects/viatra-runtime/src/main/java/tools/refinery/viatra/runtime/matchers/backend/IQueryBackendFactory.java b/subprojects/viatra-runtime/src/main/java/tools/refinery/viatra/runtime/matchers/backend/IQueryBackendFactory.java
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+++ b/subprojects/viatra-runtime/src/main/java/tools/refinery/viatra/runtime/matchers/backend/IQueryBackendFactory.java
@@ -0,0 +1,52 @@
+/*******************************************************************************
+ * Copyright (c) 2010-2014, Bergmann Gabor, Istvan Rath and Daniel Varro
+ * This program and the accompanying materials are made available under the
+ * terms of the Eclipse Public License v. 2.0 which is available at
+ * http://www.eclipse.org/legal/epl-v20.html.
+ * 
+ * SPDX-License-Identifier: EPL-2.0
+ *******************************************************************************/
+package tools.refinery.viatra.runtime.matchers.backend;
+
+import tools.refinery.viatra.runtime.matchers.context.IQueryBackendContext;
+import tools.refinery.viatra.runtime.matchers.psystem.queries.PQuery;
+
+/**
+ * A Query Backend Factory identifies a query evaluator implementation, and can create an evaluator instance (an {@link IQueryBackend}) tied to a specific VIATRA Query engine upon request. 
+ * 
+ * <p> The factory is used as a lookup key for the backend instance, 
+ *   therefore implementors should either be singletons, or implement equals() / hashCode() accordingly. 
+ * 
+ * @author Bergmann Gabor
+ *
+ */
+public interface IQueryBackendFactory {
+    
+    /**
+     * Creates a new {@link IQueryBackend} instance tied to the given context elements. 
+     * 
+     * @return an instance of the class returned by {@link #getBackendClass()} that operates in the given context.
+     * @since 1.5
+     */
+    public IQueryBackend 
+        create(IQueryBackendContext context);
+    
+    
+    /**
+     * The backend instances created by this factory are guaranteed to conform to the returned class.
+     */
+    public Class<? extends IQueryBackend> getBackendClass();
+
+    /**
+     * Calculate the required capabilities, which are needed to execute the given pattern
+     * 
+     * @since 1.4
+     */
+    public IMatcherCapability calculateRequiredCapability(PQuery query, QueryEvaluationHint hint);
+    
+    /**
+     * Returns whether the current backend is caching
+     * @since 2.0
+     */
+    public boolean isCaching();
+}