get nonInlineAncestor() {
    if (!this.isInline) {
      return this;
    }
    if (
      this.incomingInlineRelation &&
      this.incomingInlineRelation.from !== this
    ) {
      return this.incomingInlineRelation.from.nonInlineAncestor;
    } else if (this.assetGraph) {
      const incomingRelations = this.incomingRelations.filter(
        (r) => r.from !== r._to
      );
      if (incomingRelations.length > 0) {
        return incomingRelations[0].from.nonInlineAncestor;
      }
    }
    return null;
  }
Get the first non-inline ancestor asset by following the
incoming relations, ie. the first asset that has a
url. Returns the asset itself if it's not inline, and null if
the asset is inline, but not in an AssetGraph.

@type {?Asset}