moved ArrayTracker and BitMapTracker to their own files.

src/main/java/org/apache/commons/collections4/bloomfilter/ArrayTracker.java

@@ -0,0 +1,51 @@
+/*
+ * Licensed to the Apache Software Foundation (ASF) under one or more
+ * contributor license agreements.  See the NOTICE file distributed with
+ * this work for additional information regarding copyright ownership.
+ * The ASF licenses this file to You under the Apache License, Version 2.0
+ * (the "License"); you may not use this file except in compliance with
+ * the License.  You may obtain a copy of the License at
+ *
+ *      http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+package org.apache.commons.collections4.bloomfilter;
+
+import java.util.function.IntPredicate;
+
+/**
+ * An IndexTracker implementation that uses an array of integers to track whether or not a
+ * number has been seen.  Suitable for Shapes that have few hash functions.
+ * @since 4.5
+ */
+public class ArrayTracker implements IntPredicate {
+    private int[] seen;
+    private int populated;
+
+    /**
+     * Constructs the tracker based on the shape.
+     * @param shape the shape to build the tracker for.
+     */
+    ArrayTracker(Shape shape) {
+        seen = new int[shape.getNumberOfHashFunctions()];
+    }
+
+    @Override
+    public boolean test(int number) {
+        if (number < 0) {
+            throw new IndexOutOfBoundsException("number may not be less than zero. " + number);
+        }
+        for (int i = 0; i < populated; i++) {
+            if (seen[i] == number) {
+                return false;
+            }
+        }
+        seen[populated++] = number;
+        return true;
+    }
+}

src/main/java/org/apache/commons/collections4/bloomfilter/BitMapTracker.java

@@ -0,0 +1,43 @@
+/*
+ * Licensed to the Apache Software Foundation (ASF) under one or more
+ * contributor license agreements.  See the NOTICE file distributed with
+ * this work for additional information regarding copyright ownership.
+ * The ASF licenses this file to You under the Apache License, Version 2.0
+ * (the "License"); you may not use this file except in compliance with
+ * the License.  You may obtain a copy of the License at
+ *
+ *      http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+package org.apache.commons.collections4.bloomfilter;
+
+import java.util.function.IntPredicate;
+
+/**
+ * An IndexTracker implementation that uses an array of bit maps to track whether or not a
+ * number has been seen.
+ * @since 4.5
+ */
+public class BitMapTracker implements IntPredicate {
+    private long[] bits;
+
+    /**
+     * Constructs a bit map based tracker for the specified shape.
+     * @param shape The shape that is being generated.
+     */
+    BitMapTracker(Shape shape) {
+        bits = new long[BitMap.numberOfBitMaps(shape.getNumberOfBits())];
+    }
+
+    @Override
+    public boolean test(int number) {
+        boolean retval = !BitMap.contains(bits, number);
+        BitMap.set(bits, number);
+        return retval;
+    }
+}

src/main/java/org/apache/commons/collections4/bloomfilter/Hasher.java

@@ -113,61 +113,5 @@ public interface Hasher {
             }
             return tracker.test(number) ? consumer.test(number) : true;
         }
-
-        /**
-         * An IndexTracker implementation that uses an array of integers to track whether or not a
-         * number has been seen.  Suitable for Shapes that have few hash functions.
-         * @since 4.5
-         */
-        static class ArrayTracker implements IntPredicate {
-            private int[] seen;
-            private int populated;
-
-            /**
-             * Constructs the tracker based on the shape.
-             * @param shape the shape to build the tracker for.
-             */
-            ArrayTracker(Shape shape) {
-                seen = new int[shape.getNumberOfHashFunctions()];
-            }
-
-            @Override
-            public boolean test(int number) {
-                if (number < 0) {
-                    throw new IndexOutOfBoundsException("number may not be less than zero. " + number);
-                }
-                for (int i = 0; i < populated; i++) {
-                    if (seen[i] == number) {
-                        return false;
-                    }
-                }
-                seen[populated++] = number;
-                return true;
-            }
-        }
-
-        /**
-         * An IndexTracker implementation that uses an array of bit maps to track whether or not a
-         * number has been seen.
-         * @since 4.5
-         */
-        static class BitMapTracker implements IntPredicate {
-            private long[] bits;
-
-            /**
-             * Constructs a bit map based tracker for the specified shape.
-             * @param shape The shape that is being generated.
-             */
-            BitMapTracker(Shape shape) {
-                bits = new long[BitMap.numberOfBitMaps(shape.getNumberOfBits())];
-            }
-
-            @Override
-            public boolean test(int number) {
-                boolean retval = !BitMap.contains(bits, number);
-                BitMap.set(bits, number);
-                return retval;
-            }
-        }
     }
 }

src/test/java/org/apache/commons/collections4/bloomfilter/ArrayTrackerTest.java

@@ -22,7 +22,6 @@ import static org.junit.jupiter.api.Assertions.assertTrue;
 
 import java.util.function.IntPredicate;
 
-import org.apache.commons.collections4.bloomfilter.Hasher.IndexFilter.ArrayTracker;
 import org.junit.jupiter.api.Test;
 
 /**

src/test/java/org/apache/commons/collections4/bloomfilter/BitMapTrackerTest.java

@@ -21,7 +21,6 @@ import static org.junit.jupiter.api.Assertions.assertTrue;
 
 import java.util.function.IntPredicate;
 
-import org.apache.commons.collections4.bloomfilter.Hasher.IndexFilter.BitMapTracker;
 import org.junit.jupiter.api.Test;
 
 /**

src/test/java/org/apache/commons/collections4/bloomfilter/IndexFilterTest.java

@@ -29,8 +29,6 @@ import java.util.SplittableRandom;
 import java.util.concurrent.ThreadLocalRandom;
 
 import org.apache.commons.collections4.bloomfilter.Hasher.IndexFilter;
-import org.apache.commons.collections4.bloomfilter.Hasher.IndexFilter.ArrayTracker;
-import org.apache.commons.collections4.bloomfilter.Hasher.IndexFilter.BitMapTracker;
 import org.junit.jupiter.api.Test;
 import org.junit.jupiter.params.ParameterizedTest;
 import org.junit.jupiter.params.provider.CsvSource;