Markdium-What is a Mixin?

Markdium-JavaScript.js

import { dedupeMixin } from '@open-wc/dedupe-mixin';

export const LocalizeMixin = dedupeMixin(
  superclass =>
    class LocalizeMixin extends superclass {
      // this assumes a Mixin for LitElement
      static get properties() {
        return {
          locale: { type: String }
        };
      }

      updated(changedProperties) {
        super.updated(changedProperties);
        if (changedProperties.has('locale')) {
          // react to locale change
        }
      }
    },
);