diff --git a/chapter2/package-lock.json b/chapter2/package-lock.json
index 6e6a993..3c5a17f 100644
--- a/chapter2/package-lock.json
+++ b/chapter2/package-lock.json
@@ -2298,7 +2298,8 @@
         "ansi-regex": {
           "version": "2.1.1",
           "bundled": true,
-          "dev": true
+          "dev": true,
+          "optional": true
         },
         "aproba": {
           "version": "1.2.0",
@@ -2319,12 +2320,14 @@
         "balanced-match": {
           "version": "1.0.0",
           "bundled": true,
-          "dev": true
+          "dev": true,
+          "optional": true
         },
         "brace-expansion": {
           "version": "1.1.11",
           "bundled": true,
           "dev": true,
+          "optional": true,
           "requires": {
             "balanced-match": "^1.0.0",
             "concat-map": "0.0.1"
@@ -2339,17 +2342,20 @@
         "code-point-at": {
           "version": "1.1.0",
           "bundled": true,
-          "dev": true
+          "dev": true,
+          "optional": true
         },
         "concat-map": {
           "version": "0.0.1",
           "bundled": true,
-          "dev": true
+          "dev": true,
+          "optional": true
         },
         "console-control-strings": {
           "version": "1.1.0",
           "bundled": true,
-          "dev": true
+          "dev": true,
+          "optional": true
         },
         "core-util-is": {
           "version": "1.0.2",
@@ -2466,7 +2472,8 @@
         "inherits": {
           "version": "2.0.3",
           "bundled": true,
-          "dev": true
+          "dev": true,
+          "optional": true
         },
         "ini": {
           "version": "1.3.5",
@@ -2478,6 +2485,7 @@
           "version": "1.0.0",
           "bundled": true,
           "dev": true,
+          "optional": true,
           "requires": {
             "number-is-nan": "^1.0.0"
           }
@@ -2492,6 +2500,7 @@
           "version": "3.0.4",
           "bundled": true,
           "dev": true,
+          "optional": true,
           "requires": {
             "brace-expansion": "^1.1.7"
           }
@@ -2499,12 +2508,14 @@
         "minimist": {
           "version": "0.0.8",
           "bundled": true,
-          "dev": true
+          "dev": true,
+          "optional": true
         },
         "minipass": {
           "version": "2.3.5",
           "bundled": true,
           "dev": true,
+          "optional": true,
           "requires": {
             "safe-buffer": "^5.1.2",
             "yallist": "^3.0.0"
@@ -2523,6 +2534,7 @@
           "version": "0.5.1",
           "bundled": true,
           "dev": true,
+          "optional": true,
           "requires": {
             "minimist": "0.0.8"
           }
@@ -2603,7 +2615,8 @@
         "number-is-nan": {
           "version": "1.0.1",
           "bundled": true,
-          "dev": true
+          "dev": true,
+          "optional": true
         },
         "object-assign": {
           "version": "4.1.1",
@@ -2615,6 +2628,7 @@
           "version": "1.4.0",
           "bundled": true,
           "dev": true,
+          "optional": true,
           "requires": {
             "wrappy": "1"
           }
@@ -2700,7 +2714,8 @@
         "safe-buffer": {
           "version": "5.1.2",
           "bundled": true,
-          "dev": true
+          "dev": true,
+          "optional": true
         },
         "safer-buffer": {
           "version": "2.1.2",
@@ -2736,6 +2751,7 @@
           "version": "1.0.2",
           "bundled": true,
           "dev": true,
+          "optional": true,
           "requires": {
             "code-point-at": "^1.0.0",
             "is-fullwidth-code-point": "^1.0.0",
@@ -2755,6 +2771,7 @@
           "version": "3.0.1",
           "bundled": true,
           "dev": true,
+          "optional": true,
           "requires": {
             "ansi-regex": "^2.0.0"
           }
@@ -2766,18 +2783,32 @@
           "optional": true
         },
         "tar": {
-          "version": "4.4.8",
-          "bundled": true,
+          "version": "4.4.15",
+          "resolved": "https://registry.npmjs.org/tar/-/tar-4.4.15.tgz",
+          "integrity": "sha512-ItbufpujXkry7bHH9NpQyTXPbJ72iTlXgkBAYsAjDXk3Ds8t/3NfO5P4xZGy7u+sYuQUbimgzswX4uQIEeNVOA==",
           "dev": true,
           "optional": true,
           "requires": {
             "chownr": "^1.1.1",
             "fs-minipass": "^1.2.5",
-            "minipass": "^2.3.4",
-            "minizlib": "^1.1.1",
+            "minipass": "^2.8.6",
+            "minizlib": "^1.2.1",
             "mkdirp": "^0.5.0",
             "safe-buffer": "^5.1.2",
-            "yallist": "^3.0.2"
+            "yallist": "^3.0.3"
+          },
+          "dependencies": {
+            "minipass": {
+              "version": "2.9.0",
+              "resolved": "https://registry.npmjs.org/minipass/-/minipass-2.9.0.tgz",
+              "integrity": "sha512-wxfUjg9WebH+CUDX/CdbRlh5SmfZiy/hpkxaRI16Y9W56Pa75sWgd/rvFilSgrauD9NyFymP/+JFV3KwzIsJeg==",
+              "dev": true,
+              "optional": true,
+              "requires": {
+                "safe-buffer": "^5.1.2",
+                "yallist": "^3.0.0"
+              }
+            }
           }
         },
         "util-deprecate": {
@@ -2798,12 +2829,14 @@
         "wrappy": {
           "version": "1.0.2",
           "bundled": true,
-          "dev": true
+          "dev": true,
+          "optional": true
         },
         "yallist": {
           "version": "3.0.3",
           "bundled": true,
-          "dev": true
+          "dev": true,
+          "optional": true
         }
       }
     },
@@ -5947,14 +5980,28 @@
       "dev": true
     },
     "tar": {
-      "version": "2.2.1",
-      "resolved": "https://registry.npmjs.org/tar/-/tar-2.2.1.tgz",
-      "integrity": "sha1-jk0qJWwOIYXGsYrWlK7JaLg8sdE=",
+      "version": "2.2.2",
+      "resolved": "https://registry.npmjs.org/tar/-/tar-2.2.2.tgz",
+      "integrity": "sha512-FCEhQ/4rE1zYv9rYXJw/msRqsnmlje5jHP6huWeBZ704jUTy02c5AZyWujpMR1ax6mVw9NyJMfuK2CMDWVIfgA==",
       "dev": true,
       "requires": {
         "block-stream": "*",
-        "fstream": "^1.0.2",
+        "fstream": "^1.0.12",
         "inherits": "2"
+      },
+      "dependencies": {
+        "fstream": {
+          "version": "1.0.12",
+          "resolved": "https://registry.npmjs.org/fstream/-/fstream-1.0.12.tgz",
+          "integrity": "sha512-WvJ193OHa0GHPEL+AycEJgxvBEwyfRkN1vhjca23OaPVMCaLCXTd5qAu82AjTcgP1UJmytkOKb63Ypde7raDIg==",
+          "dev": true,
+          "requires": {
+            "graceful-fs": "^4.1.2",
+            "inherits": "~2.0.0",
+            "mkdirp": ">=0.5 0",
+            "rimraf": "2"
+          }
+        }
       }
     },
     "tar-fs": {