diff --git a/package.json b/package.json
index 8021b64..79e0e11 100644
--- a/package.json
+++ b/package.json
@@ -81,10 +81,10 @@
     "@aureooms/js-itertools": "4.1.0",
     "@aureooms/js-measure": "1.0.3",
     "@aureooms/js-predicate": "2.0.2",
-    "@babel/cli": "7.12.8",
-    "@babel/core": "7.12.9",
-    "@babel/preset-env": "7.12.7",
-    "@babel/register": "7.12.1",
+    "@babel/cli": "7.12.10",
+    "@babel/core": "7.12.10",
+    "@babel/preset-env": "7.12.10",
+    "@babel/register": "7.12.10",
     "ava": "3.14.0",
     "babel-plugin-transform-remove-console": "6.9.4",
     "babel-plugin-unassert": "3.0.1",
diff --git a/yarn.lock b/yarn.lock
index bbb845f..4292006 100644
--- a/yarn.lock
+++ b/yarn.lock
@@ -37,10 +37,10 @@
   resolved "https://registry.yarnpkg.com/@aureooms/js-predicate/-/js-predicate-2.0.2.tgz#0c09bfbd6616fdb9c2b8f9b894201e8807e810d9"
   integrity sha1-DAm/vWYW/bnCuPm4lCAeiAfoENk=
 
-"@babel/cli@7.12.8":
-  version "7.12.8"
-  resolved "https://registry.yarnpkg.com/@babel/cli/-/cli-7.12.8.tgz#3b24ed2fd5da353ee6f19e8935ff8c93b5fe8430"
-  integrity sha512-/6nQj11oaGhLmZiuRUfxsujiPDc9BBReemiXgIbxc+M5W+MIiFKYwvNDJvBfnGKNsJTKbUfEheKc9cwoPHAVQA==
+"@babel/cli@7.12.10":
+  version "7.12.10"
+  resolved "https://registry.yarnpkg.com/@babel/cli/-/cli-7.12.10.tgz#67a1015b1cd505bde1696196febf910c4c339a48"
+  integrity sha512-+y4ZnePpvWs1fc/LhZRTHkTesbXkyBYuOB+5CyodZqrEuETXi3zOVfpAQIdgC3lXbHLTDG9dQosxR9BhvLKDLQ==
   dependencies:
     commander "^4.0.1"
     convert-source-map "^1.1.0"
@@ -66,25 +66,24 @@
   resolved "https://registry.yarnpkg.com/@babel/compat-data/-/compat-data-7.12.7.tgz#9329b4782a7d6bbd7eef57e11addf91ee3ef1e41"
   integrity sha512-YaxPMGs/XIWtYqrdEOZOCPsVWfEoriXopnsz3/i7apYPXQ3698UFhS6dVT1KN5qOsWmVgw/FOrmQgpRaZayGsw==
 
-"@babel/core@7.12.9":
-  version "7.12.9"
-  resolved "https://registry.yarnpkg.com/@babel/core/-/core-7.12.9.tgz#fd450c4ec10cdbb980e2928b7aa7a28484593fc8"
-  integrity sha512-gTXYh3M5wb7FRXQy+FErKFAv90BnlOuNn1QkCK2lREoPAjrQCO49+HVSrFoe5uakFAF5eenS75KbO2vQiLrTMQ==
+"@babel/core@7.12.10":
+  version "7.12.10"
+  resolved "https://registry.yarnpkg.com/@babel/core/-/core-7.12.10.tgz#b79a2e1b9f70ed3d84bbfb6d8c4ef825f606bccd"
+  integrity sha512-eTAlQKq65zHfkHZV0sIVODCPGVgoo1HdBlbSLi9CqOzuZanMv2ihzY+4paiKr1mH+XmYESMAmJ/dpZ68eN6d8w==
   dependencies:
     "@babel/code-frame" "^7.10.4"
-    "@babel/generator" "^7.12.5"
+    "@babel/generator" "^7.12.10"
     "@babel/helper-module-transforms" "^7.12.1"
     "@babel/helpers" "^7.12.5"
-    "@babel/parser" "^7.12.7"
+    "@babel/parser" "^7.12.10"
     "@babel/template" "^7.12.7"
-    "@babel/traverse" "^7.12.9"
-    "@babel/types" "^7.12.7"
+    "@babel/traverse" "^7.12.10"
+    "@babel/types" "^7.12.10"
     convert-source-map "^1.7.0"
     debug "^4.1.0"
     gensync "^1.0.0-beta.1"
     json5 "^2.1.2"
     lodash "^4.17.19"
-    resolve "^1.3.2"
     semver "^5.4.1"
     source-map "^0.5.0"
 
@@ -129,6 +128,15 @@
     jsesc "^2.5.1"
     source-map "^0.5.0"
 
+"@babel/generator@^7.12.10":
+  version "7.12.10"
+  resolved "https://registry.yarnpkg.com/@babel/generator/-/generator-7.12.10.tgz#2b188fc329fb8e4f762181703beffc0fe6df3460"
+  integrity sha512-6mCdfhWgmqLdtTkhXjnIz0LcdVCd26wS2JXRtj2XY0u5klDsXBREA/pG5NVOuVnF2LUrBGNFtQkIqqTbblg0ww==
+  dependencies:
+    "@babel/types" "^7.12.10"
+    jsesc "^2.5.1"
+    source-map "^0.5.0"
+
 "@babel/generator@^7.12.5":
   version "7.12.5"
   resolved "https://registry.yarnpkg.com/@babel/generator/-/generator-7.12.5.tgz#a2c50de5c8b6d708ab95be5e6053936c1884a4de"
@@ -436,6 +444,11 @@
   resolved "https://registry.yarnpkg.com/@babel/parser/-/parser-7.12.1.tgz#dc03f543a0ed51396d4081463df66ecb3a2efa53"
   integrity sha512-xjZsx0sBjb6J2+QkoHI69UeD2EWbsyUW0WyZKOoJ9sBrQLxfOApWEefR9dIVOYJVj97VRXnLKLDvnn3dPDNgww==
 
+"@babel/parser@^7.12.10":
+  version "7.12.10"
+  resolved "https://registry.yarnpkg.com/@babel/parser/-/parser-7.12.10.tgz#824600d59e96aea26a5a2af5a9d812af05c3ae81"
+  integrity sha512-PJdRPwyoOqFAWfLytxrWwGrAxghCgh/yTNCYciOz8QgjflA7aZhECPZAa2VUedKg2+QMWkI0L9lynh2SNmNEgA==
+
 "@babel/parser@^7.12.7":
   version "7.12.7"
   resolved "https://registry.yarnpkg.com/@babel/parser/-/parser-7.12.7.tgz#fee7b39fe809d0e73e5b25eecaf5780ef3d73056"
@@ -875,10 +888,10 @@
   dependencies:
     "@babel/helper-plugin-utils" "^7.10.4"
 
-"@babel/plugin-transform-typeof-symbol@^7.12.1":
-  version "7.12.1"
-  resolved "https://registry.yarnpkg.com/@babel/plugin-transform-typeof-symbol/-/plugin-transform-typeof-symbol-7.12.1.tgz#9ca6be343d42512fbc2e68236a82ae64bc7af78a"
-  integrity sha512-EPGgpGy+O5Kg5pJFNDKuxt9RdmTgj5sgrus2XVeMp/ZIbOESadgILUbm50SNpghOh3/6yrbsH+NB5+WJTmsA7Q==
+"@babel/plugin-transform-typeof-symbol@^7.12.10":
+  version "7.12.10"
+  resolved "https://registry.yarnpkg.com/@babel/plugin-transform-typeof-symbol/-/plugin-transform-typeof-symbol-7.12.10.tgz#de01c4c8f96580bd00f183072b0d0ecdcf0dec4b"
+  integrity sha512-JQ6H8Rnsogh//ijxspCjc21YPd3VLVoYtAwv3zQmqAt8YGYUtdo5usNhdl4b9/Vir2kPFZl6n1h0PfUz4hJhaA==
   dependencies:
     "@babel/helper-plugin-utils" "^7.10.4"
 
@@ -897,10 +910,10 @@
     "@babel/helper-create-regexp-features-plugin" "^7.12.1"
     "@babel/helper-plugin-utils" "^7.10.4"
 
-"@babel/preset-env@7.12.7":
-  version "7.12.7"
-  resolved "https://registry.yarnpkg.com/@babel/preset-env/-/preset-env-7.12.7.tgz#54ea21dbe92caf6f10cb1a0a576adc4ebf094b55"
-  integrity sha512-OnNdfAr1FUQg7ksb7bmbKoby4qFOHw6DKWWUNB9KqnnCldxhxJlP+21dpyaWFmf2h0rTbOkXJtAGevY3XW1eew==
+"@babel/preset-env@7.12.10":
+  version "7.12.10"
+  resolved "https://registry.yarnpkg.com/@babel/preset-env/-/preset-env-7.12.10.tgz#ca981b95f641f2610531bd71948656306905e6ab"
+  integrity sha512-Gz9hnBT/tGeTE2DBNDkD7BiWRELZt+8lSysHuDwmYXUIvtwZl0zI+D6mZgXZX0u8YBlLS4tmai9ONNY9tjRgRA==
   dependencies:
     "@babel/compat-data" "^7.12.7"
     "@babel/helper-compilation-targets" "^7.12.5"
@@ -961,12 +974,12 @@
     "@babel/plugin-transform-spread" "^7.12.1"
     "@babel/plugin-transform-sticky-regex" "^7.12.7"
     "@babel/plugin-transform-template-literals" "^7.12.1"
-    "@babel/plugin-transform-typeof-symbol" "^7.12.1"
+    "@babel/plugin-transform-typeof-symbol" "^7.12.10"
     "@babel/plugin-transform-unicode-escapes" "^7.12.1"
     "@babel/plugin-transform-unicode-regex" "^7.12.1"
     "@babel/preset-modules" "^0.1.3"
-    "@babel/types" "^7.12.7"
-    core-js-compat "^3.7.0"
+    "@babel/types" "^7.12.10"
+    core-js-compat "^3.8.0"
     semver "^5.5.0"
 
 "@babel/preset-modules@^0.1.3":
@@ -980,10 +993,10 @@
     "@babel/types" "^7.4.4"
     esutils "^2.0.2"
 
-"@babel/register@7.12.1":
-  version "7.12.1"
-  resolved "https://registry.yarnpkg.com/@babel/register/-/register-7.12.1.tgz#cdb087bdfc4f7241c03231f22e15d211acf21438"
-  integrity sha512-XWcmseMIncOjoydKZnWvWi0/5CUCD+ZYKhRwgYlWOrA8fGZ/FjuLRpqtIhLOVD/fvR1b9DQHtZPn68VvhpYf+Q==
+"@babel/register@7.12.10":
+  version "7.12.10"
+  resolved "https://registry.yarnpkg.com/@babel/register/-/register-7.12.10.tgz#19b87143f17128af4dbe7af54c735663b3999f60"
+  integrity sha512-EvX/BvMMJRAA3jZgILWgbsrHwBQvllC5T8B29McyME8DvkdOxk4ujESfrMvME8IHSDvWXrmMXxPvA/lx2gqPLQ==
   dependencies:
     find-cache-dir "^2.0.0"
     lodash "^4.17.19"
@@ -1054,25 +1067,25 @@
     globals "^11.1.0"
     lodash "^4.17.19"
 
-"@babel/traverse@^7.12.5":
-  version "7.12.7"
-  resolved "https://registry.yarnpkg.com/@babel/traverse/-/traverse-7.12.7.tgz#572a722408681cef17d6b0bef69ef2e728ca69f1"
-  integrity sha512-nMWaqsQEeSvMNypswUDzjqQ+0rR6pqCtoQpsqGJC4/Khm9cISwPTSpai57F6/jDaOoEGz8yE/WxcO3PV6tKSmQ==
+"@babel/traverse@^7.12.10":
+  version "7.12.10"
+  resolved "https://registry.yarnpkg.com/@babel/traverse/-/traverse-7.12.10.tgz#2d1f4041e8bf42ea099e5b2dc48d6a594c00017a"
+  integrity sha512-6aEtf0IeRgbYWzta29lePeYSk+YAFIC3kyqESeft8o5CkFlYIMX+EQDDWEiAQ9LHOA3d0oHdgrSsID/CKqXJlg==
   dependencies:
     "@babel/code-frame" "^7.10.4"
-    "@babel/generator" "^7.12.5"
+    "@babel/generator" "^7.12.10"
     "@babel/helper-function-name" "^7.10.4"
     "@babel/helper-split-export-declaration" "^7.11.0"
-    "@babel/parser" "^7.12.7"
-    "@babel/types" "^7.12.7"
+    "@babel/parser" "^7.12.10"
+    "@babel/types" "^7.12.10"
     debug "^4.1.0"
     globals "^11.1.0"
     lodash "^4.17.19"
 
-"@babel/traverse@^7.12.9":
-  version "7.12.9"
-  resolved "https://registry.yarnpkg.com/@babel/traverse/-/traverse-7.12.9.tgz#fad26c972eabbc11350e0b695978de6cc8e8596f"
-  integrity sha512-iX9ajqnLdoU1s1nHt36JDI9KG4k+vmI8WgjK5d+aDTwQbL2fUnzedNedssA645Ede3PM2ma1n8Q4h2ohwXgMXw==
+"@babel/traverse@^7.12.5":
+  version "7.12.7"
+  resolved "https://registry.yarnpkg.com/@babel/traverse/-/traverse-7.12.7.tgz#572a722408681cef17d6b0bef69ef2e728ca69f1"
+  integrity sha512-nMWaqsQEeSvMNypswUDzjqQ+0rR6pqCtoQpsqGJC4/Khm9cISwPTSpai57F6/jDaOoEGz8yE/WxcO3PV6tKSmQ==
   dependencies:
     "@babel/code-frame" "^7.10.4"
     "@babel/generator" "^7.12.5"
@@ -1111,6 +1124,15 @@
     lodash "^4.17.19"
     to-fast-properties "^2.0.0"
 
+"@babel/types@^7.12.10":
+  version "7.12.10"
+  resolved "https://registry.yarnpkg.com/@babel/types/-/types-7.12.10.tgz#7965e4a7260b26f09c56bcfcb0498af1f6d9b260"
+  integrity sha512-sf6wboJV5mGyip2hIpDSKsr80RszPinEFjsHTalMxZAZkoQ2/2yQzxlcFN52SJqsyPfLtPmenL4g2KB3KJXPDw==
+  dependencies:
+    "@babel/helper-validator-identifier" "^7.10.4"
+    lodash "^4.17.19"
+    to-fast-properties "^2.0.0"
+
 "@babel/types@^7.12.5", "@babel/types@^7.12.7":
   version "7.12.7"
   resolved "https://registry.yarnpkg.com/@babel/types/-/types-7.12.7.tgz#6039ff1e242640a29452c9ae572162ec9a8f5d13"
@@ -1815,7 +1837,7 @@ braces@^3.0.1, braces@~3.0.2:
   dependencies:
     fill-range "^7.0.1"
 
-browserslist@^4.14.5, browserslist@^4.14.6:
+browserslist@^4.14.5:
   version "4.14.7"
   resolved "https://registry.yarnpkg.com/browserslist/-/browserslist-4.14.7.tgz#c071c1b3622c1c2e790799a37bb09473a4351cb6"
   integrity sha512-BSVRLCeG3Xt/j/1cCGj1019Wbty0H+Yvu2AOuZSuoaUWn3RatbL33Cxk+Q4jRMRAbOm0p7SLravLjpnT6s0vzQ==
@@ -1826,6 +1848,17 @@ browserslist@^4.14.5, browserslist@^4.14.6:
     escalade "^3.1.1"
     node-releases "^1.1.66"
 
+browserslist@^4.15.0:
+  version "4.15.0"
+  resolved "https://registry.yarnpkg.com/browserslist/-/browserslist-4.15.0.tgz#3d48bbca6a3f378e86102ffd017d9a03f122bdb0"
+  integrity sha512-IJ1iysdMkGmjjYeRlDU8PQejVwxvVO5QOfXH7ylW31GO6LwNRSmm/SgRXtNsEXqMLl2e+2H5eEJ7sfynF8TCaQ==
+  dependencies:
+    caniuse-lite "^1.0.30001164"
+    colorette "^1.2.1"
+    electron-to-chromium "^1.3.612"
+    escalade "^3.1.1"
+    node-releases "^1.1.67"
+
 buffer-from@^1.0.0:
   version "1.1.1"
   resolved "https://registry.yarnpkg.com/buffer-from/-/buffer-from-1.1.1.tgz#32713bc028f75c02fdb710d7c7bcec1f2c6070ef"
@@ -1934,6 +1967,11 @@ caniuse-lite@^1.0.30001157:
   resolved "https://registry.yarnpkg.com/caniuse-lite/-/caniuse-lite-1.0.30001159.tgz#bebde28f893fa9594dadcaa7d6b8e2aa0299df20"
   integrity sha512-w9Ph56jOsS8RL20K9cLND3u/+5WASWdhC/PPrf+V3/HsM3uHOavWOR1Xzakbv4Puo/srmPHudkmCRWM7Aq+/UA==
 
+caniuse-lite@^1.0.30001164:
+  version "1.0.30001165"
+  resolved "https://registry.yarnpkg.com/caniuse-lite/-/caniuse-lite-1.0.30001165.tgz#32955490d2f60290bb186bb754f2981917fa744f"
+  integrity sha512-8cEsSMwXfx7lWSUMA2s08z9dIgsnR5NAqjXP23stdsU3AUWkCr/rr4s4OFtHXn5XXr6+7kam3QFVoYyXNPdJPA==
+
 caseless@~0.12.0:
   version "0.12.0"
   resolved "https://registry.yarnpkg.com/caseless/-/caseless-0.12.0.tgz#1b681c21ff84033c826543090689420d187151dc"
@@ -2291,12 +2329,12 @@ copy-descriptor@^0.1.0:
   resolved "https://registry.yarnpkg.com/copy-descriptor/-/copy-descriptor-0.1.1.tgz#676f6eb3c39997c2ee1ac3a924fd6124748f578d"
   integrity sha1-Z29us8OZl8LuGsOpJP1hJHSPV40=
 
-core-js-compat@^3.7.0:
-  version "3.7.0"
-  resolved "https://registry.yarnpkg.com/core-js-compat/-/core-js-compat-3.7.0.tgz#8479c5d3d672d83f1f5ab94cf353e57113e065ed"
-  integrity sha512-V8yBI3+ZLDVomoWICO6kq/CD28Y4r1M7CWeO4AGpMdMfseu8bkSubBmUPySMGKRTS+su4XQ07zUkAsiu9FCWTg==
+core-js-compat@^3.8.0:
+  version "3.8.1"
+  resolved "https://registry.yarnpkg.com/core-js-compat/-/core-js-compat-3.8.1.tgz#8d1ddd341d660ba6194cbe0ce60f4c794c87a36e"
+  integrity sha512-a16TLmy9NVD1rkjUGbwuyWkiDoN0FDpAwrfLONvHFQx0D9k7J9y0srwMT8QP/Z6HE3MIFaVynEeYwZwPX1o5RQ==
   dependencies:
-    browserslist "^4.14.6"
+    browserslist "^4.15.0"
     semver "7.0.0"
 
 core-js-pure@^3.0.0:
@@ -2671,6 +2709,11 @@ electron-to-chromium@^1.3.591:
   resolved "https://registry.yarnpkg.com/electron-to-chromium/-/electron-to-chromium-1.3.603.tgz#1b71bec27fb940eccd79245f6824c63d5f7e8abf"
   integrity sha512-J8OHxOeJkoSLgBXfV9BHgKccgfLMHh+CoeRo6wJsi6m0k3otaxS/5vrHpMNSEYY4MISwewqanPOuhAtuE8riQQ==
 
+electron-to-chromium@^1.3.612:
+  version "1.3.621"
+  resolved "https://registry.yarnpkg.com/electron-to-chromium/-/electron-to-chromium-1.3.621.tgz#0bbe2100ef0b28f88d0b1101fbdf433312f69be0"
+  integrity sha512-FeIuBzArONbAmKmZIsZIFGu/Gc9AVGlVeVbhCq+G2YIl6QkT0TDn2HKN/FMf1btXEB9kEmIuQf3/lBTVAbmFOg==
+
 elegant-spinner@^1.0.1:
   version "1.0.1"
   resolved "https://registry.yarnpkg.com/elegant-spinner/-/elegant-spinner-1.0.1.tgz#db043521c95d7e303fd8f345bedc3349cfb0729e"
@@ -4805,7 +4848,7 @@ node-preload@^0.2.1:
   dependencies:
     process-on-spawn "^1.0.0"
 
-node-releases@^1.1.66:
+node-releases@^1.1.66, node-releases@^1.1.67:
   version "1.1.67"
   resolved "https://registry.yarnpkg.com/node-releases/-/node-releases-1.1.67.tgz#28ebfcccd0baa6aad8e8d4d8fe4cbc49ae239c12"
   integrity sha512-V5QF9noGFl3EymEwUYzO+3NTDpGfQB4ve6Qfnzf3UNydMhjQRVPR1DZTuvWiLzaFJYw2fmDwAfnRNEVb64hSIg==