docs: public boolean isValidStartContextForContentKind(SanitizedContentKind contentKind) {
      if (templateNestDepth != 0) {
        return false;
      }
      switch (contentKind) {
        case ATTRIBUTES:
          // Allow HTML attribute names, regardless of the kind of attribute (e.g. plain text)
          // or immediately after an open tag.
          return state == HtmlContext.HTML_ATTRIBUTE_NAME || state == HtmlContext.HTML_TAG;
        default:
          // NOTE: For URI's, we need to be picky that the context has no attribute type, since we
          // don't want to forget to escape ampersands.
          return this.equals(getStartContextForContentKind(contentKind));
      }
    }