🚨 Error: Cannot call a class constructor without |new|

Details
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**Error report:** [link](http://go/ampe/COrG8rfHg9297wE)
**First seen:** Nov 17, 2020
**Frequency:** ~ 545/day

Stacktrace
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Error: Cannot call a class constructor without |new|

    at element (src/base-element.js:110:14)

    at extensions/amp-lightbox/0.1/amp-lightbox.js:101:4

    at classList (src/custom-element.js:360:6)

    at src/custom-element.js:82:46

    at holder (src/service/extensions-impl.js:162:6)

    at src/service/custom-element-registry.js:52:4

    at src/style-installer.js:104:7

    at src/service/custom-element-registry.js:52:4

    at holder (src/service/extensions-impl.js:410:4)

    at extensionId (src/service/extensions-impl.js:459:43)

    at holder (src/service/extensions-impl.js:410:4)

    at TAG (extensions/amp-lightbox/0.1/amp-lightbox.js:46:12)

    at self (extensions/amp-lightbox/0.1/amp-lightbox.js:943:0)

    at getExtensionHolder_ (src/service/extensions-impl.js:190:20)

    at Extensions (src/service/extensions-impl.js:115:47)

Notes
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`@cramforce` modified `extensions/amp-lightbox/0.1/amp-lightbox.js:99-102` in #5602 (Oct 14, 2016)
`@jridgewell` modified `src/custom-element.js:82-83` in #27470 (Mar 30, 2020)
`@dvoytenko` modified `src/service/extensions-impl.js:156-179` in #4025 (Jul 15, 2016)
`@rsimha` modified `src/service/custom-element-registry.js:50-56` in #21212 (May 16, 2019)
`@rsimha` modified `src/style-installer.js:101-105` in #21212 (May 16, 2019)
`@rsimha` modified `src/service/custom-element-registry.js:50-56` in #21212 (May 16, 2019)
`@dvoytenko` modified `src/service/extensions-impl.js:409-411` in #4025 (Jul 15, 2016)
`@dvoytenko` modified `src/service/extensions-impl.js:457-461` in #29358 (Jul 20, 2020)
`@dvoytenko` modified `src/service/extensions-impl.js:409-411` in #4025 (Jul 15, 2016)
`@muxin` modified `extensions/amp-lightbox/0.1/amp-lightbox.js:45-46` in #6398 (Dec 7, 2016)
`@renovate-bot` modified `extensions/amp-lightbox/0.1/amp-lightbox.js:943-943` in #27350 (Mar 30, 2020)
`@rsimha` modified `src/service/extensions-impl.js:186-192` in #21212 (May 16, 2019)
`@kmh287` modified `src/service/extensions-impl.js:115-115` in #7858 (Mar 21, 2017)

**Seen in:**
- 11-07 Control (0101+1)
- 11-07 Nightly-Control (0101+1)
- 11-07 Stable (0101+1)
- 11-14 Beta (0244+2)
- 11-14 Experiment-A (0244+2)
- 11-14 Experimental (0244+2)

**Possible assignees:** `@dvoytenko`, `@jridgewell`

/cc @ampproject/release-on-duty

Trace the stack from src/base-element.js:110 through extensions/amp-lightbox/0.1/amp-lightbox.js:101 and the referenced custom-element and extensions service files. Compare the affected release channels and investigate the constructor call path. The issue does not define a specific fix or acceptance test, so completion would require confirming the error no longer occurs across the listed channels.

Written by the indexing model from the issue text.