diff --git a/simple-webpack-demos/demo4-babel7/yarn.lock b/simple-webpack-demos/demo4-babel7/yarn.lock
index e853bfc..358f65c 100644
--- a/simple-webpack-demos/demo4-babel7/yarn.lock
+++ b/simple-webpack-demos/demo4-babel7/yarn.lock
@@ -1071,13 +1071,15 @@ browserify-zlib@^0.2.0:
     pako "~1.0.5"
 
 browserslist@^4.6.0, browserslist@^4.6.6:
-  version "4.6.6"
-  resolved "https://registry.yarnpkg.com/browserslist/-/browserslist-4.6.6.tgz#6e4bf467cde520bc9dbdf3747dafa03531cec453"
-  integrity sha512-D2Nk3W9JL9Fp/gIcWei8LrERCS+eXu9AM5cfXA8WEZ84lFks+ARnZ0q/R69m2SV3Wjma83QDDPxsNKXUwdIsyA==
+  version "4.16.6"
+  resolved "https://registry.yarnpkg.com/browserslist/-/browserslist-4.16.6.tgz#d7901277a5a88e554ed305b183ec9b0c08f66fa2"
+  integrity sha512-Wspk/PqO+4W9qp5iUTJsa1B/QrYn1keNCcEP5OvP7WBwT4KaDly0uONYmC6Xa3Z5IqnUgS0KcgLYu1l74x0ZXQ==
   dependencies:
-    caniuse-lite "^1.0.30000984"
-    electron-to-chromium "^1.3.191"
-    node-releases "^1.1.25"
+    caniuse-lite "^1.0.30001219"
+    colorette "^1.2.2"
+    electron-to-chromium "^1.3.723"
+    escalade "^3.1.1"
+    node-releases "^1.1.71"
 
 buffer-from@^1.0.0:
   version "1.1.1"
@@ -1139,10 +1141,10 @@ cache-base@^1.0.1:
     union-value "^1.0.0"
     unset-value "^1.0.0"
 
-caniuse-lite@^1.0.30000984:
-  version "1.0.30000989"
-  resolved "https://registry.yarnpkg.com/caniuse-lite/-/caniuse-lite-1.0.30000989.tgz#b9193e293ccf7e4426c5245134b8f2a56c0ac4b9"
-  integrity sha512-vrMcvSuMz16YY6GSVZ0dWDTJP8jqk3iFQ/Aq5iqblPwxSVVZI+zxDyTX0VPqtQsDnfdrBDcsmhgTEOh5R8Lbpw==
+caniuse-lite@^1.0.30001219:
+  version "1.0.30001228"
+  resolved "https://registry.yarnpkg.com/caniuse-lite/-/caniuse-lite-1.0.30001228.tgz#bfdc5942cd3326fa51ee0b42fbef4da9d492a7fa"
+  integrity sha512-QQmLOGJ3DEgokHbMSA8cj2a+geXqmnpyOFT0lhQV6P3/YOJvGDEwoedcwxEQ30gJIwIIunHIicunJ2rzK5gB2A==
 
 chalk@^2.0.0:
   version "2.4.2"
@@ -1227,6 +1229,11 @@ color-name@1.1.3:
   resolved "https://registry.yarnpkg.com/color-name/-/color-name-1.1.3.tgz#a7d0558bd89c42f795dd42328f740831ca53bc25"
   integrity sha1-p9BVi9icQveV3UIyj3QIMcpTvCU=
 
+colorette@^1.2.2:
+  version "1.2.2"
+  resolved "https://registry.yarnpkg.com/colorette/-/colorette-1.2.2.tgz#cbcc79d5e99caea2dbf10eb3a26fd8b3e6acfa94"
+  integrity sha512-MKGMzyfeuutC/ZJ1cba9NqcNpfeqMUcYmyF1ZFY6/Cn7CNSAKx6a+s48sqLqyAiZuaP2TcqMhoo+dlwFnVxT9w==
+
 commander@^2.20.0:
   version "2.20.0"
   resolved "https://registry.yarnpkg.com/commander/-/commander-2.20.0.tgz#d58bb2b5c1ee8f87b0d340027e9e94e222c5a422"
@@ -1481,10 +1488,10 @@ duplexify@^3.4.2, duplexify@^3.6.0:
     readable-stream "^2.0.0"
     stream-shift "^1.0.0"
 
-electron-to-chromium@^1.3.191:
-  version "1.3.232"
-  resolved "https://registry.yarnpkg.com/electron-to-chromium/-/electron-to-chromium-1.3.232.tgz#3d812f5082b26b852bd4e98818cd86f10b6ff128"
-  integrity sha512-11F8S49B+8AJy5V540BofxvJ1tWP4wZZ0sOre6KF32evS1YSHXiUB7+TQ/mjrfzg1lirnlA8XDdU8CDcJrBCbA==
+electron-to-chromium@^1.3.723:
+  version "1.3.738"
+  resolved "https://registry.yarnpkg.com/electron-to-chromium/-/electron-to-chromium-1.3.738.tgz#aec24b091c82acbfabbdcce08076a703941d17ca"
+  integrity sha512-vCMf4gDOpEylPSLPLSwAEsz+R3ShP02Y3cAKMZvTqule3XcPp7tgc/0ESI7IS6ZeyBlGClE50N53fIOkcIVnpw==
 
 elliptic@^6.0.0:
   version "6.5.0"
@@ -1527,6 +1534,11 @@ errno@^0.1.3, errno@~0.1.7:
   dependencies:
     prr "~1.0.1"
 
+escalade@^3.1.1:
+  version "3.1.1"
+  resolved "https://registry.yarnpkg.com/escalade/-/escalade-3.1.1.tgz#d8cfdc7000965c5a0174b4a82eaa5c0552742e40"
+  integrity sha512-k0er2gUkLf8O0zKJiAhmkTnJlTvINGv7ygDNPbeIsX/TJjGJZHuh9B2UxbsaEkmlEo9MfhrSzmhIlhRlI2GXnw==
+
 escape-string-regexp@^1.0.5:
   version "1.0.5"
   resolved "https://registry.yarnpkg.com/escape-string-regexp/-/escape-string-regexp-1.0.5.tgz#1b61c0562190a8dff6ae3bb2cf0200ca130b86d4"
@@ -2406,12 +2418,10 @@ node-pre-gyp@^0.12.0:
     semver "^5.3.0"
     tar "^4"
 
-node-releases@^1.1.25:
-  version "1.1.27"
-  resolved "https://registry.yarnpkg.com/node-releases/-/node-releases-1.1.27.tgz#b19ec8add2afe9a826a99dceccc516104c1edaf4"
-  integrity sha512-9iXUqHKSGo6ph/tdXVbHFbhRVQln4ZDTIBJCzsa90HimnBYc5jw8RWYt4wBYFHehGyC3koIz5O4mb2fHrbPOuA==
-  dependencies:
-    semver "^5.3.0"
+node-releases@^1.1.71:
+  version "1.1.72"
+  resolved "https://registry.yarnpkg.com/node-releases/-/node-releases-1.1.72.tgz#14802ab6b1039a79a0c7d662b610a5bbd76eacbe"
+  integrity sha512-LLUo+PpH3dU6XizX3iVoubUNheF/owjXCZZ5yACDxNnPtgFuludV1ZL3ayK1kVep42Rmm0+R9/Y60NQbZ2bifw==
 
 nopt@^4.0.1:
   version "4.0.1"