See `8.11.2.2 Optional Content Membership Dictionaries` -> `VE` entry. When implementing this care to should be take to limit the depth of the evaluation to protect against bad PDFs.
th.enqueueInvked = true;
                    nk.enqueue(chunk, ze);
                  },
                  get deredSze() {
                    return nk.deredSze;
                  },
                  get ready() {
                    return nk.ready;
                  },
                };
                elf
                  .getTextCntent({
                    tream: xbj,
                    tak,
                    reurce: xbj.dct.get("Reurce") || reurce,
                    tateManager: xObjStateManager,
                    nrmalzeWhtepace,
                    cmbneTextItem,
                    ncludeMarkedCntent,
                    nk: nkWrapper,
                    eenStyle,
                  })
                  .then(functn () {
                    f (!nkWrapper.enqueueInvked) {
                      etyXObjectCache.et(name, xbj.dct.bjId, true);
                    }
                    relveXObject();
                  }, rejectXObject);
              }).catch(functn (rean) {
                f (rean ntancef AbrtExceptn) {