diff --git a/Chapter04/Server/package-lock.json b/Chapter04/Server/package-lock.json
index 6f51023..5cdf004 100644
--- a/Chapter04/Server/package-lock.json
+++ b/Chapter04/Server/package-lock.json
@@ -17,7 +17,6 @@
       "version": "1.0.11",
       "resolved": "https://registry.npmjs.org/@types/bson/-/bson-1.0.11.tgz",
       "integrity": "sha512-j+UcCWI+FsbI5/FQP/Kj2CXyplWAz39ktHFkXk84h7dNblKRSoNJs95PZFRd96NQGqsPEPgeclqnznWZr14ZDA==",
-      "dev": true,
       "requires": {
         "@types/node": "*"
       }
@@ -196,14 +195,6 @@
       "integrity": "sha1-WWZ/QfrdTyDMvCu5a41Pf3jsA2c=",
       "dev": true
     },
-    "async": {
-      "version": "2.6.1",
-      "resolved": "https://registry.npmjs.org/async/-/async-2.6.1.tgz",
-      "integrity": "sha512-fNEiL2+AZt6AlAw/29Cr0UDe4sRAHCpEHh54WMz+Bb7QfNcFw4h3loofyJpLeQs4Yx7yuqu/2dLgM5hKOs6HlQ==",
-      "requires": {
-        "lodash": "^4.17.10"
-      }
-    },
     "async-each": {
       "version": "1.0.1",
       "resolved": "https://registry.npmjs.org/async-each/-/async-each-1.0.1.tgz",
@@ -283,6 +274,15 @@
       "integrity": "sha512-DYWGk01lDcxeS/K9IHPGWfT8PsJmbXRtRd2Sx72Tnb8pcYZQFF1oSDb8hJtS1vhp212q1Rzi5dUf9+nq0o9UIg==",
       "dev": true
     },
+    "bl": {
+      "version": "2.2.1",
+      "resolved": "https://registry.npmjs.org/bl/-/bl-2.2.1.tgz",
+      "integrity": "sha512-6Pesp1w0DEX1N550i/uGV/TqucVL4AM/pgThFSN/Qq9si1/DF9aIHs1BxD8V/QU0HoeHO6cQRTAuYnLPKq1e4g==",
+      "requires": {
+        "readable-stream": "^2.3.5",
+        "safe-buffer": "^5.1.1"
+      }
+    },
     "bluebird": {
       "version": "3.5.1",
       "resolved": "https://registry.npmjs.org/bluebird/-/bluebird-3.5.1.tgz",
@@ -360,9 +360,9 @@
       }
     },
     "bson": {
-      "version": "1.1.0",
-      "resolved": "https://registry.npmjs.org/bson/-/bson-1.1.0.tgz",
-      "integrity": "sha512-9Aeai9TacfNtWXOYarkFJRW2CWo+dRon+fuLZYJmvLV3+MiUp0bEI6IAZfXEIg7/Pl/7IWlLaDnhzTsD81etQA=="
+      "version": "1.1.6",
+      "resolved": "https://registry.npmjs.org/bson/-/bson-1.1.6.tgz",
+      "integrity": "sha512-EvVNVeGo4tHxwi8L6bPj3y3itEvStdwvvlojVxxbyYfoaxJ6keLgrTuKdyfEAszFK+H3olzBuafE0yoh0D1gdg=="
     },
     "buffer-from": {
       "version": "1.1.1",
@@ -691,6 +691,11 @@
         }
       }
     },
+    "denque": {
+      "version": "1.5.1",
+      "resolved": "https://registry.npmjs.org/denque/-/denque-1.5.1.tgz",
+      "integrity": "sha512-XwE+iZ4D6ZUB7mfYRMb5wByE8L74HCn30FBN7sWnXksWc1LO1bPDl67pBR9o/kC4z/xSNAwkMYcGgqDV3BE3Hw=="
+    },
     "depd": {
       "version": "1.1.2",
       "resolved": "https://registry.npmjs.org/depd/-/depd-1.1.2.tgz",
@@ -1035,7 +1040,8 @@
         "ansi-regex": {
           "version": "2.1.1",
           "bundled": true,
-          "dev": true
+          "dev": true,
+          "optional": true
         },
         "aproba": {
           "version": "1.2.0",
@@ -1056,12 +1062,14 @@
         "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"
@@ -1076,17 +1084,20 @@
         "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",
@@ -1203,7 +1214,8 @@
         "inherits": {
           "version": "2.0.3",
           "bundled": true,
-          "dev": true
+          "dev": true,
+          "optional": true
         },
         "ini": {
           "version": "1.3.5",
@@ -1215,6 +1227,7 @@
           "version": "1.0.0",
           "bundled": true,
           "dev": true,
+          "optional": true,
           "requires": {
             "number-is-nan": "^1.0.0"
           }
@@ -1229,6 +1242,7 @@
           "version": "3.0.4",
           "bundled": true,
           "dev": true,
+          "optional": true,
           "requires": {
             "brace-expansion": "^1.1.7"
           }
@@ -1236,12 +1250,14 @@
         "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"
@@ -1260,6 +1276,7 @@
           "version": "0.5.1",
           "bundled": true,
           "dev": true,
+          "optional": true,
           "requires": {
             "minimist": "0.0.8"
           }
@@ -1340,7 +1357,8 @@
         "number-is-nan": {
           "version": "1.0.1",
           "bundled": true,
-          "dev": true
+          "dev": true,
+          "optional": true
         },
         "object-assign": {
           "version": "4.1.1",
@@ -1352,6 +1370,7 @@
           "version": "1.4.0",
           "bundled": true,
           "dev": true,
+          "optional": true,
           "requires": {
             "wrappy": "1"
           }
@@ -1437,7 +1456,8 @@
         "safe-buffer": {
           "version": "5.1.2",
           "bundled": true,
-          "dev": true
+          "dev": true,
+          "optional": true
         },
         "safer-buffer": {
           "version": "2.1.2",
@@ -1473,6 +1493,7 @@
           "version": "1.0.2",
           "bundled": true,
           "dev": true,
+          "optional": true,
           "requires": {
             "code-point-at": "^1.0.0",
             "is-fullwidth-code-point": "^1.0.0",
@@ -1492,6 +1513,7 @@
           "version": "3.0.1",
           "bundled": true,
           "dev": true,
+          "optional": true,
           "requires": {
             "ansi-regex": "^2.0.0"
           }
@@ -1535,12 +1557,14 @@
         "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
         }
       }
     },
@@ -1914,9 +1938,9 @@
       "dev": true
     },
     "kareem": {
-      "version": "2.3.0",
-      "resolved": "https://registry.npmjs.org/kareem/-/kareem-2.3.0.tgz",
-      "integrity": "sha512-6hHxsp9e6zQU8nXsP+02HGWXwTkOEw6IROhF2ZA28cYbUk4eJ6QbtZvdqZOdD9YPKghG3apk5eOCvs+tLl3lRg=="
+      "version": "2.3.2",
+      "resolved": "https://registry.npmjs.org/kareem/-/kareem-2.3.2.tgz",
+      "integrity": "sha512-STHz9P7X2L4Kwn72fA4rGyqyXdmrMSdxqHx9IXon/FXluXieaFA6KJ2upcHAHxQPQ0LeM/OjLrhFxifHewOALQ=="
     },
     "kind-of": {
       "version": "6.0.2",
@@ -1933,11 +1957,6 @@
         "package-json": "^4.0.0"
       }
     },
-    "lodash": {
-      "version": "4.17.11",
-      "resolved": "https://registry.npmjs.org/lodash/-/lodash-4.17.11.tgz",
-      "integrity": "sha512-cQKh8igo5QUhZ7lg38DYWAxMvjSAKG0A8wGSVimP07SIUEK2UO+arSRKbRZWtelMtN5V0Hkwh5ryOto/SshYIg=="
-    },
     "lodash.debounce": {
       "version": "4.0.8",
       "resolved": "https://registry.npmjs.org/lodash.debounce/-/lodash.debounce-4.0.8.tgz",
@@ -2102,42 +2121,68 @@
       }
     },
     "mongodb": {
-      "version": "3.1.10",
-      "resolved": "https://registry.npmjs.org/mongodb/-/mongodb-3.1.10.tgz",
-      "integrity": "sha512-Uml42GeFxhTGQVml1XQ4cD0o/rp7J2ROy0fdYUcVitoE7vFqEhKH4TYVqRDpQr/bXtCJVxJdNQC1ntRxNREkPQ==",
-      "requires": {
-        "mongodb-core": "3.1.9",
-        "safe-buffer": "^5.1.2"
-      }
-    },
-    "mongodb-core": {
-      "version": "3.1.9",
-      "resolved": "https://registry.npmjs.org/mongodb-core/-/mongodb-core-3.1.9.tgz",
-      "integrity": "sha512-MJpciDABXMchrZphh3vMcqu8hkNf/Mi+Gk6btOimVg1XMxLXh87j6FAvRm+KmwD1A9fpu3qRQYcbQe4egj23og==",
-      "requires": {
-        "bson": "^1.1.0",
-        "require_optional": "^1.0.1",
+      "version": "3.7.3",
+      "resolved": "https://registry.npmjs.org/mongodb/-/mongodb-3.7.3.tgz",
+      "integrity": "sha512-Psm+g3/wHXhjBEktkxXsFMZvd3nemI0r3IPsE0bU+4//PnvNWKkzhZcEsbPcYiWqe8XqXJJEg4Tgtr7Raw67Yw==",
+      "requires": {
+        "bl": "^2.2.1",
+        "bson": "^1.1.4",
+        "denque": "^1.4.1",
+        "optional-require": "^1.1.8",
         "safe-buffer": "^5.1.2",
         "saslprep": "^1.0.0"
+      },
+      "dependencies": {
+        "optional-require": {
+          "version": "1.1.8",
+          "resolved": "https://registry.npmjs.org/optional-require/-/optional-require-1.1.8.tgz",
+          "integrity": "sha512-jq83qaUb0wNg9Krv1c5OQ+58EK+vHde6aBPzLvPPqJm89UQWsvSuFy9X/OSNJnFeSOKo7btE0n8Nl2+nE+z5nA==",
+          "requires": {
+            "require-at": "^1.0.6"
+          }
+        }
       }
     },
     "mongoose": {
-      "version": "5.4.8",
-      "resolved": "https://registry.npmjs.org/mongoose/-/mongoose-5.4.8.tgz",
-      "integrity": "sha512-2wgBi1LBxL/pcG0nNP8zXBLRmWZFzg8pb2MH4JkMPIxP/HGtQQEP0DbG1Yzy+Igsp3M1+V/59uXW37O2Fg5mBQ==",
-      "requires": {
-        "async": "2.6.1",
-        "bson": "~1.1.0",
-        "kareem": "2.3.0",
-        "mongodb": "3.1.10",
-        "mongodb-core": "3.1.9",
+      "version": "5.13.15",
+      "resolved": "https://registry.npmjs.org/mongoose/-/mongoose-5.13.15.tgz",
+      "integrity": "sha512-cxp1Gbb8yUWkaEbajdhspSaKzAvsIvOtRlYD87GN/P2QEUhpd6bIvebi36T6M0tIVAMauNaK9SPA055N3PwF8Q==",
+      "requires": {
+        "@types/bson": "1.x || 4.0.x",
+        "@types/mongodb": "^3.5.27",
+        "bson": "^1.1.4",
+        "kareem": "2.3.2",
+        "mongodb": "3.7.3",
         "mongoose-legacy-pluralize": "1.0.2",
-        "mpath": "0.5.1",
-        "mquery": "3.2.0",
-        "ms": "2.0.0",
-        "regexp-clone": "0.0.1",
-        "safe-buffer": "5.1.2",
+        "mpath": "0.8.4",
+        "mquery": "3.2.5",
+        "ms": "2.1.2",
+        "optional-require": "1.0.x",
+        "regexp-clone": "1.0.0",
+        "safe-buffer": "5.2.1",
+        "sift": "13.5.2",
         "sliced": "1.0.1"
+      },
+      "dependencies": {
+        "@types/mongodb": {
+          "version": "3.6.20",
+          "resolved": "https://registry.npmjs.org/@types/mongodb/-/mongodb-3.6.20.tgz",
+          "integrity": "sha512-WcdpPJCakFzcWWD9juKoZbRtQxKIMYF/JIAM4JrNHrMcnJL6/a2NWjXxW7fo9hxboxxkg+icff8d7+WIEvKgYQ==",
+          "requires": {
+            "@types/bson": "*",
+            "@types/node": "*"
+          }
+        },
+        "ms": {
+          "version": "2.1.2",
+          "resolved": "https://registry.npmjs.org/ms/-/ms-2.1.2.tgz",
+          "integrity": "sha512-sGkPx+VjMtmA6MX27oA4FBFELFCZZ4S4XqeGOXCv68tT+jb3vk/RyaKWP0PTKyWtmLSM0b+adUTEvbs1PEaH2w=="
+        },
+        "safe-buffer": {
+          "version": "5.2.1",
+          "resolved": "https://registry.npmjs.org/safe-buffer/-/safe-buffer-5.2.1.tgz",
+          "integrity": "sha512-rp3So07KcdmmKbGvgaNxQSJr7bGVSVk5S9Eq1F+ppbRo70+YeaDxkw5Dd8NPN+GD6bjnYm2VuPuCXmpuYvmCXQ=="
+        }
       }
     },
     "mongoose-legacy-pluralize": {
@@ -2146,18 +2191,18 @@
       "integrity": "sha512-Yo/7qQU4/EyIS8YDFSeenIvXxZN+ld7YdV9LqFVQJzTLye8unujAWPZ4NWKfFA+RNjh+wvTWKY9Z3E5XM6ZZiQ=="
     },
     "mpath": {
-      "version": "0.5.1",
-      "resolved": "https://registry.npmjs.org/mpath/-/mpath-0.5.1.tgz",
-      "integrity": "sha512-H8OVQ+QEz82sch4wbODFOz+3YQ61FYz/z3eJ5pIdbMEaUzDqA268Wd+Vt4Paw9TJfvDgVKaayC0gBzMIw2jhsg=="
+      "version": "0.8.4",
+      "resolved": "https://registry.npmjs.org/mpath/-/mpath-0.8.4.tgz",
+      "integrity": "sha512-DTxNZomBcTWlrMW76jy1wvV37X/cNNxPW1y2Jzd4DZkAaC5ZGsm8bfGfNOthcDuRJujXLqiuS6o3Tpy0JEoh7g=="
     },
     "mquery": {
-      "version": "3.2.0",
-      "resolved": "https://registry.npmjs.org/mquery/-/mquery-3.2.0.tgz",
-      "integrity": "sha512-qPJcdK/yqcbQiKoemAt62Y0BAc0fTEKo1IThodBD+O5meQRJT/2HSe5QpBNwaa4CjskoGrYWsEyjkqgiE0qjhg==",
+      "version": "3.2.5",
+      "resolved": "https://registry.npmjs.org/mquery/-/mquery-3.2.5.tgz",
+      "integrity": "sha512-VjOKHHgU84wij7IUoZzFRU07IAxd5kWJaDmyUzQlbjHjyoeK5TNeeo8ZsFDtTYnSgpW6n/nMNIHvE3u8Lbrf4A==",
       "requires": {
         "bluebird": "3.5.1",
         "debug": "3.1.0",
-        "regexp-clone": "0.0.1",
+        "regexp-clone": "^1.0.0",
         "safe-buffer": "5.1.2",
         "sliced": "1.0.1"
       },
@@ -5355,6 +5400,11 @@
         "ee-first": "1.1.1"
       }
     },
+    "optional-require": {
+      "version": "1.0.3",
+      "resolved": "https://registry.npmjs.org/optional-require/-/optional-require-1.0.3.tgz",
+      "integrity": "sha512-RV2Zp2MY2aeYK5G+B/Sps8lW5NHAzE5QClbFP15j+PWmP+T9PxlJXBOOLoSAdgwFvS4t0aMR4vpedMkbHfh0nA=="
+    },
     "p-finally": {
       "version": "1.0.0",
       "resolved": "https://registry.npmjs.org/p-finally/-/p-finally-1.0.0.tgz",
@@ -5526,9 +5576,9 @@
       }
     },
     "regexp-clone": {
-      "version": "0.0.1",
-      "resolved": "https://registry.npmjs.org/regexp-clone/-/regexp-clone-0.0.1.tgz",
-      "integrity": "sha1-p8LgmJH9vzj7sQ03b7cwA+aKxYk="
+      "version": "1.0.0",
+      "resolved": "https://registry.npmjs.org/regexp-clone/-/regexp-clone-1.0.0.tgz",
+      "integrity": "sha512-TuAasHQNamyyJ2hb97IuBEif4qBHGjPHBS64sZwytpLEqtBQ1gPJTnOaQ6qmpET16cK14kkjbazl6+p0RRv0yw=="
     },
     "registry-auth-token": {
       "version": "3.3.2",
@@ -5567,19 +5617,10 @@
       "integrity": "sha1-jcrkcOHIirwtYA//Sndihtp15jc=",
       "dev": true
     },
-    "require_optional": {
-      "version": "1.0.1",
-      "resolved": "https://registry.npmjs.org/require_optional/-/require_optional-1.0.1.tgz",
-      "integrity": "sha512-qhM/y57enGWHAe3v/NcwML6a3/vfESLe/sGM2dII+gEO0BpKRUkWZow/tyloNqJyN6kXSl3RyyM8Ll5D/sJP8g==",
-      "requires": {
-        "resolve-from": "^2.0.0",
-        "semver": "^5.1.0"
-      }
-    },
-    "resolve-from": {
-      "version": "2.0.0",
-      "resolved": "https://registry.npmjs.org/resolve-from/-/resolve-from-2.0.0.tgz",
-      "integrity": "sha1-lICrIOlP+h2egKgEx+oUdhGWa1c="
+    "require-at": {
+      "version": "1.0.6",
+      "resolved": "https://registry.npmjs.org/require-at/-/require-at-1.0.6.tgz",
+      "integrity": "sha512-7i1auJbMUrXEAZCOQ0VNJgmcT2VOKPRl2YGJwgpHpC9CE91Mv4/4UYIUm4chGJaI381ZDq1JUicFii64Hapd8g=="
     },
     "resolve-url": {
       "version": "0.2.1",
@@ -5613,9 +5654,9 @@
       "integrity": "sha512-YZo3K82SD7Riyi0E1EQPojLz7kpepnSQI9IyPbHHg1XXXevb5dJI7tpyN2ADxGcQbHG7vcyRHk0cbwqcQriUtg=="
     },
     "saslprep": {
-      "version": "1.0.2",
-      "resolved": "https://registry.npmjs.org/saslprep/-/saslprep-1.0.2.tgz",
-      "integrity": "sha512-4cDsYuAjXssUSjxHKRe4DTZC0agDwsCqcMqtJAQPzC74nJ7LfAJflAtC1Zed5hMzEQKj82d3tuzqdGNRsLJ4Gw==",
+      "version": "1.0.3",
+      "resolved": "https://registry.npmjs.org/saslprep/-/saslprep-1.0.3.tgz",
+      "integrity": "sha512-/MY/PEMbk2SuY5sScONwhUDsV2p77Znkb/q3nSVstq/yQzYJOH/Azh29p9oJLsl3LnQwSvZDKagDGBsBwSooag==",
       "optional": true,
       "requires": {
         "sparse-bitfield": "^3.0.3"
@@ -5624,7 +5665,8 @@
     "semver": {
       "version": "5.6.0",
       "resolved": "https://registry.npmjs.org/semver/-/semver-5.6.0.tgz",
-      "integrity": "sha512-RS9R6R35NYgQn++fkDWaOmqGoj4Ek9gGs+DPxNUZKuwE183xjJroKvyo1IzVFeXvUrvmALy6FWD5xrdJT25gMg=="
+      "integrity": "sha512-RS9R6R35NYgQn++fkDWaOmqGoj4Ek9gGs+DPxNUZKuwE183xjJroKvyo1IzVFeXvUrvmALy6FWD5xrdJT25gMg==",
+      "dev": true
     },
     "semver-diff": {
       "version": "2.1.0",
@@ -5709,6 +5751,11 @@
       "integrity": "sha1-2kL0l0DAtC2yypcoVxyxkMmO/qM=",
       "dev": true
     },
+    "sift": {
+      "version": "13.5.2",
+      "resolved": "https://registry.npmjs.org/sift/-/sift-13.5.2.tgz",
+      "integrity": "sha512-+gxdEOMA2J+AI+fVsCqeNn7Tgx3M9ZN9jdi95939l1IJ8cZsqS8sqpJyOkic2SJk+1+98Uwryt/gL6XDaV+UZA=="
+    },
     "signal-exit": {
       "version": "3.0.2",
       "resolved": "https://registry.npmjs.org/signal-exit/-/signal-exit-3.0.2.tgz",
@@ -5718,7 +5765,7 @@
     "sliced": {
       "version": "1.0.1",
       "resolved": "https://registry.npmjs.org/sliced/-/sliced-1.0.1.tgz",
-      "integrity": "sha1-CzpmK10Ewxd7GSa+qCsD+Dei70E="
+      "integrity": "sha512-VZBmZP8WU3sMOZm1bdgTadsQbcscK0UM8oKxKVBs4XAhUo2Xxzm/OFMGBkPusxw9xL3Uy8LrzEqGqJhclsr0yA=="
     },
     "snapdragon": {
       "version": "0.8.2",
@@ -5873,7 +5920,7 @@
     "sparse-bitfield": {
       "version": "3.0.3",
       "resolved": "https://registry.npmjs.org/sparse-bitfield/-/sparse-bitfield-3.0.3.tgz",
-      "integrity": "sha1-/0rm5oZWBWuks+eSqzM004JzyhE=",
+      "integrity": "sha512-kvzhi7vqKTfkh0PZU+2D2PIllw2ymqJKujUcyPMd9Y75Nv4nPbGJZXNhxsgdQab2BmlDct1YnfQCguEvHr7VsQ==",
       "optional": true,
       "requires": {
         "memory-pager": "^1.0.2"