checkKind = (specimen, kind, check) => {
    // check null and undefined as Keys
    if (singletonKinds.has(kind)) {
      // eslint-disable-next-line no-use-before-define
      return checkAsKeyPatt(specimen, singletonKinds.get(kind), check);
    }

    const realKind = kindOf(specimen, check);
    if (kind === realKind) {
      return true;
    }
    if (check !== identChecker) {
      // `kind` and `realKind` can be embedded without quotes
      // because they are drawn from the enumerated collection of known Kinds.
      check(false, X`${b(realKind)} ${specimen} - Must be a ${b(kind)}`);
    }
    return false;
  }
Checks only recognized kinds, and only if the specimen
passes the invariants associated with that recognition.

@param {any} specimen
@param {Kind} kind
@param {Checker} check
@returns {boolean}