Added some tests.

Mage.Sets/src/mage/sets/khansoftarkir/SidisiBroodTyrant.java

@@ -143,6 +143,7 @@ class SidisiBroodTyrantTriggeredAbility extends ZoneChangeTriggeredAbility {
                 if (stackObject == null) {
                     stackObject = (StackObject) game.getLastKnownInformation(event.getSourceId(), Zone.STACK);
                 }
+                // If multiple cards go to graveyard from replacement effect (e.g. Dredge) each card is wrongly handled as a new event
                 if (stackObject != null) {
                     if (stackObject.getId().equals(lastStackObjectId)) {
                         return false; // was already handled

Mage.Tests/src/test/java/org/mage/test/cards/abilities/keywords/DredgeTest.java

@@ -0,0 +1,81 @@
+/*
+ *  Copyright 2010 BetaSteward_at_googlemail.com. All rights reserved.
+ *
+ *  Redistribution and use in source and binary forms, with or without modification, are
+ *  permitted provided that the following conditions are met:
+ *
+ *     1. Redistributions of source code must retain the above copyright notice, this list of
+ *        conditions and the following disclaimer.
+ *
+ *     2. Redistributions in binary form must reproduce the above copyright notice, this list
+ *        of conditions and the following disclaimer in the documentation and/or other materials
+ *        provided with the distribution.
+ *
+ *  THIS SOFTWARE IS PROVIDED BY BetaSteward_at_googlemail.com ``AS IS'' AND ANY EXPRESS OR IMPLIED
+ *  WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND
+ *  FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL BetaSteward_at_googlemail.com OR
+ *  CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
+ *  CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR
+ *  SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON
+ *  ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING
+ *  NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF
+ *  ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+ *
+ *  The views and conclusions contained in the software and documentation are those of the
+ *  authors and should not be interpreted as representing official policies, either expressed
+ *  or implied, of BetaSteward_at_googlemail.com.
+ */
+package org.mage.test.cards.abilities.keywords;
+
+import mage.constants.PhaseStep;
+import mage.constants.Zone;
+import org.junit.Test;
+import org.mage.test.serverside.base.CardTestPlayerBase;
+
+/**
+ *
+ * @author LevelX2
+ */
+
+public class DredgeTest extends CardTestPlayerBase {
+    /**
+     *  702.51. Dredge
+     *   702.51a Dredge is a static ability that functions only while the card with dredge is in a player's graveyard. "Dredge N" means "As long as you have at least N cards in your library, if you would draw a card, you may instead put N cards from the top of your library into your graveyard and return this card from your graveyard to your hand."
+     *   702.51b A player with fewer cards in his or her library than the number required by a dredge ability can't put any of them into his or her graveyard this way.
+     */
+
+    
+   /**
+    *    Had a Sidisi, Brood Tyrant in play and dredge a Stinkweed Imp hitting 3 creatures.
+    *    and Sidisi triggered 3 times instead of just one.
+    */
+    @Test
+    public void testDredgeWithSidisiBroodTyrant() {        
+        // Whenever Sidisi, Brood Tyrant enters the battlefield or attacks, put the top three cards of your library into your graveyard.
+        // Whenever one or more creature cards are put into your graveyard from your library, put a 2/2 black Zombie creature token onto the battlefield.
+        addCard(Zone.BATTLEFIELD, playerB, "Sidisi, Brood Tyrant");
+        // Flying
+        // Whenever Stinkweed Imp deals combat damage to a creature, destroy that creature.
+        // Dredge 5
+        addCard(Zone.GRAVEYARD, playerB, "Stinkweed Imp");
+        
+        addCard(Zone.LIBRARY, playerB, "Silvercoat Lion", 5);
+        skipInitShuffling();
+        
+        setChoice(playerB, "Yes"); // Use Dredge
+
+        setStopAt(2, PhaseStep.PRECOMBAT_MAIN);
+        execute();
+
+        assertLife(playerA, 20);
+        assertLife(playerB, 20);
+
+        assertHandCount(playerB, "Stinkweed Imp", 1);
+        assertGraveyardCount(playerB, "Silvercoat Lion", 5);
+        
+        assertPermanentCount(playerB, "Zombie", 1); // May only be one creature
+        
+    }
+
+
+}

Mage.Tests/src/test/java/org/mage/test/cards/watchers/SiftThroughSandsTest.java

@@ -59,7 +59,7 @@ public class SiftThroughSandsTest extends CardTestPlayerBase {
     }
 
     // TODO: This test fails sometimes if building the complete test project
-    // cause is still unknown
+    // The cause is still unknown
     
     // test that The Unspeakable is not put onto the battlefield
     @Test