if (fields != null) {
                        docMap.putAll(fields.entrySet()
                                .stream()
                                .collect(Collectors.toMap(Entry::getKey, e -> (Object) e.getValue().getValues())));
                    }

                    final ViewHelper viewHelper = ComponentUtil.getViewHelper();

            final String key = e.getKey();
            if (StringUtil.isBlank(key)) {
                return false;
            }
            return pattern.matcher(key).matches();
        }).collect(Collectors.toMap(Entry<String, String>::getKey, Entry<String, String>::getValue));
    }

    /**
     * Gets a map of environment variables.
     *
     * @return A map of environment variables.
     */