docs: function getParts(struct, parts) {
      parts = parts || [];
      for (var i = 0; i < struct.length; i++) {
          if (Array.isArray(struct[i])) {
              getParts(struct[i], parts);
          } else if (struct[i].partID) {
              parts.push(struct[i]);
          }
      }
      return parts;
  }