hotfix: Remove the problematic @immutable annotation.

Author: jkozlowski

suffix-tree/pom.xml

@@ -33,11 +33,6 @@
             <artifactId>guava</artifactId>
             <version>${guava.version}</version>
         </dependency>
-        <dependency>
-            <groupId>com.google.code.findbugs</groupId>
-            <artifactId>findbugs</artifactId>
-            <version>${findbugs.version}</version>
-        </dependency>
         <dependency>
             <groupId>diffr</groupId>
             <artifactId>util</artifactId>

suffix-tree/src/main/java/diffr/suffixtree/impl/Edge.java

@@ -7,7 +7,6 @@
 import diffr.util.ListIterators;
 import javolution.util.FastCollection.Record;
 
-import javax.annotation.concurrent.Immutable;
 import java.util.ListIterator;
 
 import static com.google.common.base.Preconditions.checkArgument;
@@ -23,7 +22,6 @@
  * @author Jakub D Kozlowski
  * @since 0.1
  */
-@Immutable
 public final class Edge {
 
     private final Record parent;

suffix-tree/src/main/java/diffr/suffixtree/impl/NodeKey.java

@@ -4,8 +4,6 @@
 import diffr.suffixtree.SuffixTree;
 import javolution.util.FastCollection.Record;
 
-import javax.annotation.concurrent.Immutable;
-
 import static com.google.common.base.Preconditions.checkNotNull;
 
 /**
@@ -16,7 +14,6 @@
  * @author Jakub D Kozlowski
  * @since 0.1
  */
-@Immutable
 public final class NodeKey<E extends Comparable> {
 
     private final Record parent;