* set of the empty set is not the empty set, but a one-element set containing the empty set.
   *
   * <p>The returned set and its constituent sets use {@code equals} to decide whether two elements
   * are identical, even if the input set uses a different concept of equivalence.
   *
   * <p><i>Performance notes:</i> while the power set of a set with size {@code n} is of size {@code

 * because unequal URLs may be equal because of how they are hosted.
 *
 * ### Equal URLs should be equal
 *
 * These two URLs are semantically identical, but `java.net.URI` disagrees:
 *
 *  * http://host:80/
 *
 *  * http://host
 *
 * Both the unnecessary port specification (`:80`) and the absent trailing slash (`/`) cause URI to

		HTTPStatusCode: http.StatusBadRequest,
	},
	ErrBucketRemoteIdenticalToSource: {
		Code:           "XMinioAdminRemoteIdenticalToSource",
		Description:    "The remote target cannot be identical to source",
		HTTPStatusCode: http.StatusBadRequest,
	},
	ErrBucketRemoteAlreadyExists: {
		Code:           "XMinioAdminBucketRemoteAlreadyExists",
		Description:    "The remote target already exists",

			lookupRes, actualGroups, _ := sys.LDAPConfig.GetValidatedDNWithGroups(user)
			if lookupRes != nil {
				groupSet := set.CreateStringSet(actualGroups...)

				// duplicates can be overwritten, fetched groups should be identical.
				cleanQ.Users[lookupRes.NormDN] = groupSet
			}
			// Search for non-normalized DN as well for backward compatibility.
			if _, ok := cleanQ.Users[user]; !ok {
				cleanQ.Users[user] = nil
			}
		}

		}
		// Make sure to return object info to provide extra information.
		return toObjectErr(errMethodNotAllowed, bucket, object)
	}
	// verify that the object queued for transition is identical to that on disk.
	if !opts.MTime.Equal(fi.ModTime) || !strings.EqualFold(opts.Transition.ETag, extractETag(fi.Metadata)) {
		return toObjectErr(errFileNotFound, bucket, object)
	}