code: protected String[] toStringArray(final Object value) {
          if (value instanceof String[]) {
              return (String[]) value;
          } else if (value instanceof List) {
              return ((List<?>) value).stream().map(v -> v.toString()).toArray(n -> new String[n]);
          }
          String str = DfTypeUtil.toString(value);
          if (str == null) {
              return null;
          }
          return new String[] { str };
      }
docs: ============