* {@code joiner}.
   *
   * <p><b>{@code Stream} equivalent:</b> {@code joiner.join(stream.iterator())}, or, if you are not
   * using any optional {@code Joiner} features, {@code
   * stream.collect(Collectors.joining(delimiter)}.
   *
   * @since 18.0
   */
  public final String join(Joiner joiner) {
    return joiner.join(this);
  }

  /**

                            .filter(StringUtil::isNotBlank).distinct().collect(Collectors.joining("\n")));
                    form.virtualHosts = stream(entity.getVirtualHosts())
                            .get(stream -> stream.filter(StringUtil::isNotBlank).map(String::trim).collect(Collectors.joining("\n")));
                    form.name = null;
                });
                form.crudMode = CrudMode.CREATE;

                            .filter(StringUtil::isNotBlank).distinct().collect(Collectors.joining("\n")));
                    form.virtualHosts = stream(entity.getVirtualHosts())
                            .get(stream -> stream.filter(StringUtil::isNotBlank).map(String::trim).collect(Collectors.joining("\n")));
                    form.name = null;
                });
                form.crudMode = CrudMode.CREATE;

        valueMap.put("user", user.map(FessUserBean::getUserId).orElse("-"));
        valueMap.put("permissions",
                user.map(u -> stream(u.getPermissions()).get(stream -> stream.collect(Collectors.joining(permissionSeparator))))
                        .filter(StringUtil::isNotBlank).orElse("-"));
        log(valueMap);
    }

    public void loginFailure(final OptionalThing<LoginCredential> credential) {

                            logger.warn("{}", errors.stream().collect(Collectors.joining(", ")));
                            if (auth.isDebugActive() && StringUtil.isNotBlank(auth.getLastErrorReason())) {
                                logger.warn("Authentication Failure: {} - Reason: {}", errors.stream().collect(Collectors.joining(", ")),
                                        auth.getLastErrorReason());

							}
						}
					} else {
						fromClause.Joins = append(fromClause.Joins, clause.Join{
							Expression: clause.NamedExpr{SQL: join.Name, Vars: join.Conds},
						})
					}
				} else {
					fromClause.Joins = append(fromClause.Joins, clause.Join{
						Expression: clause.NamedExpr{SQL: join.Name, Vars: join.Conds},
					})
				}
			}

			db.Statement.AddClause(fromClause)
		} else {

                .filter(StringUtil::isNotBlank).distinct().collect(Collectors.joining("\n")));
        body.virtualHosts = stream(entity.getVirtualHosts())
                .get(stream -> stream.filter(StringUtil::isNotBlank).distinct().map(String::trim).collect(Collectors.joining("\n")));
        return body;
    }

            append(b, "used", () -> p.getUsed().getBytes()).append(',');
            append(b, "capacity", () -> p.getTotalCapacity().getBytes()).append('}');
            return b.toString();
        }).collect(Collectors.joining(",")));
        buf.append("},");
        final GarbageCollectors gc = jvmStats.getGc();
        buf.append("\"gc\":{");
        buf.append(Arrays.stream(gc.getCollectors()).map(c -> {

    assertEquals("", j.join(ImmutableMultimap.of().entries()));
    assertEquals("", j.join(ImmutableMultimap.of().entries().iterator()));
    assertEquals(":", j.join(ImmutableMultimap.of("", "").entries()));
    assertEquals(":", j.join(ImmutableMultimap.of("", "").entries().iterator()));
    assertEquals("1:a;1:b", j.join(ImmutableMultimap.of("1", "a", "1", "b").entries()));

                return StringUtils.join(newInputs, ",");
            }
            return StringUtils.join(newInputs, ",") + "=>" + StringUtils.join(newOutputs, ",");
        }
        if (Arrays.equals(inputs, outputs)) {
            return StringUtils.join(inputs, ",");
        }
        return StringUtils.join(inputs, ",") + "=>" + StringUtils.join(outputs, ",");
    }