resolveToExistingVersion(info) {
    // get final resolved version
    var _normalizePattern2 = (0, (_normalizePattern4 || _load_normalizePattern()).normalizePattern)(this.pattern);

    const range = _normalizePattern2.range,
          name = _normalizePattern2.name;

    const solvedRange = (_semver || _load_semver()).default.validRange(range) ? info.version : range;
    const resolved = this.resolver.getHighestRangeVersionMatch(name, solvedRange, info);
    (0, (_invariant || _load_invariant()).default)(resolved, 'should have a resolved reference');

    this.reportResolvedRangeMatch(info, resolved);
    const ref = resolved._reference;
    (0, (_invariant || _load_invariant()).default)(ref, 'Resolved package info has no package reference');
    ref.addRequest(this);
    ref.addPattern(this.pattern, resolved);
    ref.addOptional(this.optional);
  }
Do the final resolve of a package that had a match with an existing version.
After all unique versions have been discovered, so the best available version
is found.