Remove apache commons dependency

pom.xml

@@ -144,11 +144,6 @@
             <artifactId>jackson-core</artifactId>
             <version>${jackson.version}</version>
         </dependency>
-        <dependency>
-            <groupId>org.apache.commons</groupId>
-            <artifactId>commons-collections4</artifactId>
-            <version>4.2</version>
-        </dependency>
         <dependency>
             <scope>test</scope>
             <groupId>commons-io</groupId>

src/main/java/com/flipkart/zjsonpatch/EditScript.java

@@ -0,0 +1,147 @@
+/*
+ * Copyright 2021 flipkart.com zjsonpatch.
+ *
+ * Licensed 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 com.flipkart.zjsonpatch;
+
+import java.util.ArrayList;
+import java.util.List;
+
+import com.flipkart.zjsonpatch.InternalUtils.CommandVisitor;
+import com.flipkart.zjsonpatch.InternalUtils.DeleteCommand;
+import com.flipkart.zjsonpatch.InternalUtils.EditCommand;
+import com.flipkart.zjsonpatch.InternalUtils.InsertCommand;
+import com.flipkart.zjsonpatch.InternalUtils.KeepCommand;
+
+/**
+ * This class gathers all the {@link EditCommand commands} needed to transform
+ * one objects sequence into another objects sequence.
+ * <p>
+ * An edit script is the most general view of the differences between two
+ * sequences. It is built as the result of the comparison between two sequences
+ * by the {@link SequencesComparator SequencesComparator} class. The user can
+ * walk through it using the <em>visitor</em> design pattern.
+ * </p>
+ * <p>
+ * It is guaranteed that the objects embedded in the {@link InsertCommand insert
+ * commands} come from the second sequence and that the objects embedded in
+ * either the {@link DeleteCommand delete commands} or {@link KeepCommand keep
+ * commands} come from the first sequence. This can be important if subclassing
+ * is used for some elements in the first sequence and the {@code equals}
+ * method is specialized.
+ * </p>
+ * <p>
+ * ATTRIBUTION NOTICE:<br>
+ * This class contains source code copied from <a href="https://github.com/apache/commons-collections/tree/9414e73a7b8c5434b7cfcc5a65fc9baa007a1861">
+ * Apache commons-collection4
+ * <a>
+ * </p>
+ * 
+ * @see SequencesComparator
+ * @see EditCommand
+ * @see CommandVisitor
+ * @see ReplacementsHandler
+ *
+ * @since 4.0
+ */
+public class EditScript<T> {
+
+    /** Container for the commands. */
+    private final List<EditCommand<T>> commands;
+
+    /** Length of the longest common subsequence. */
+    private int lcsLength;
+
+    /** Number of modifications. */
+    private int modifications;
+
+    /**
+     * Simple constructor. Creates a new empty script.
+     */
+    public EditScript() {
+        commands = new ArrayList<>();
+        lcsLength = 0;
+        modifications = 0;
+    }
+
+    /**
+     * Add a keep command to the script.
+     *
+     * @param command  command to add
+     */
+    public void append(final KeepCommand<T> command) {
+        commands.add(command);
+        ++lcsLength;
+    }
+
+    /**
+     * Add an insert command to the script.
+     *
+     * @param command  command to add
+     */
+    public void append(final InsertCommand<T> command) {
+        commands.add(command);
+        ++modifications;
+    }
+
+    /**
+     * Add a delete command to the script.
+     *
+     * @param command  command to add
+     */
+    public void append(final DeleteCommand<T> command) {
+        commands.add(command);
+        ++modifications;
+    }
+
+    /**
+     * Visit the script. The script implements the <em>visitor</em> design
+     * pattern, this method is the entry point to which the user supplies its
+     * own visitor, the script will be responsible to drive it through the
+     * commands in order and call the appropriate method as each command is
+     * encountered.
+     *
+     * @param visitor  the visitor that will visit all commands in turn
+     */
+    public void visit(final CommandVisitor<T> visitor) {
+        for (final EditCommand<T> command : commands) {
+            command.accept(visitor);
+        }
+    }
+
+    /**
+     * Get the length of the Longest Common Subsequence (LCS). The length of the
+     * longest common subsequence is the number of {@link KeepCommand keep
+     * commands} in the script.
+     *
+     * @return length of the Longest Common Subsequence
+     */
+    public int getLCSLength() {
+        return lcsLength;
+    }
+
+    /**
+     * Get the number of effective modifications. The number of effective
+     * modification is the number of {@link DeleteCommand delete} and
+     * {@link InsertCommand insert} commands in the script.
+     *
+     * @return number of effective modifications
+     */
+    public int getModifications() {
+        return modifications;
+    }
+
+
+}