[BLB] Implement Ruthless Negotiation

Mage/src/main/java/mage/abilities/condition/common/CastFromGraveyardSourceCondition.java

@@ -0,0 +1,32 @@
+package mage.abilities.condition.common;
+
+import mage.abilities.Ability;
+import mage.abilities.condition.Condition;
+import mage.constants.Zone;
+import mage.game.Game;
+import mage.game.stack.Spell;
+
+import java.util.Optional;
+
+/**
+ * @author TheElk801
+ */
+public enum CastFromGraveyardSourceCondition implements Condition {
+    instance;
+
+    @Override
+    public boolean apply(Game game, Ability source) {
+        return Optional
+                .ofNullable(source)
+                .map(Ability::getSourceId)
+                .map(game::getSpell)
+                .map(Spell::getFromZone)
+                .map(Zone.GRAVEYARD::match)
+                .orElse(false);
+    }
+
+    @Override
+    public String toString() {
+        return "this spell was cast from a graveyard";
+    }
+}