private boolean isLiteral(int c) throws IOException {
    switch (c) {
      case '/':
      case '\\':
      case ';':
      case '#':
      case '=':
        checkLenient(); // fall-through
      case '{':
      case '}':
      case '[':
      case ']':
      case ':':
      case ',':
      case ' ':
      case '\t':
      case '\f':
      case '\r':
      case '\n':
        return false;
      default:
        return true;
    }
  }
A peeked string that should be parsed on the next double, long or string.
This is populated before a numeric value is parsed and used if that parsing
fails.
lottie/src/main/java/com/airbnb/lottie/parser/moshi/JsonUtf8Reader.java