#vulnerable code 
                             private final void newWrongTokenException(String awaited, int cursor) {
		// otherwise it fails when an error occurs on first character
		if (cursor < 0) cursor = 0;
		int pos = (_position - valueAsString().length() - _buflen + cursor);
		if (pos < 0) pos = 0;

		if (_buflen < 0)
			throw new IllegalStateException(
					"Incomplete data or malformed json : encoutered end of stream but expected "
							+ awaited);
		else
			throw new IllegalStateException("Illegal character at position " + pos + " expected "
					+ awaited + " but read '" + _buffer[cursor] + "' !");
	} 
                            #location 4 
                            #vulnerability type NULL_DEREFERENCE
#fixed code
                             private final void newWrongTokenException(String awaited, int cursor) {
		// otherwise it fails when an error occurs on first character
		if (cursor < 0) cursor = 0;
		int pos = _position - (_buflen - cursor);
		if (pos < 0) pos = 0;

		if (_buflen < 0)
			throw new IllegalStateException(
					"Incomplete data or malformed json : encoutered end of stream but expected "
							+ awaited);
		else
			throw new IllegalStateException("Illegal character at position " + pos + " expected "
					+ awaited + " but read '" + _buffer[cursor] + "' !");
	}