add apply patch example

test/examples/diffutils/ApplyPatch.java

@@ -0,0 +1,27 @@
+package diffutils;
+
+import java.io.File;
+import java.util.List;
+
+import difflib.DiffUtils;
+import difflib.Patch;
+import difflib.PatchFailedException;
+
+public class ApplyPatch extends Example {
+    static final String FS = File.separator;
+    static final String ORIGINAL = "test" + FS + "mocks" + FS + "issue10_base.txt";
+    static final String PATCH = "test" + FS + "mocks" + FS + "issue10_patch.txt";
+
+    public static void main(String[] args) throws PatchFailedException {
+        List<String> original = fileToLines(ORIGINAL);
+        List<String> patched  = fileToLines(PATCH);
+
+     // At first, parse the unified diff file and get the patch
+        Patch patch = DiffUtils.parseUnifiedDiff(patched);
+
+        // Then apply the computed patch to the given text
+        List result = DiffUtils.patch(original, patch);
+        System.out.println(result);
+        /// Or we can call patch.applyTo(original). There is no difference.
+    }
+}