@Override
          public String nextString() throws IOException {
            JsonToken peeked = peek();
            if (peeked == JsonToken.STRING) {
              return super.nextString();
            }
            throw new JsonParseException(
                String.format("In strict mode (!lenient) string read only from string literal, not %s. Path: %s",
                    peeked,
                    getPath()));
          }
Forces creation of more strict in string reading if in !lenient mode
gson/src/org/immutables/gson/stream/GsonMessageBodyProvider.java