public static long decodeLongBase64(String val) {
    	long res = 0;
    	for(int i=0;i<val.length();++i) {
    		int chunk = decode[val.charAt(i)];
    		if (chunk < 0)
    			throw new NumberFormatException("Bad base64 encoding");
    		res <<= 6;
    		res |= chunk;
    	}
    	return res;
    }
Decode (up to 11) base64 characters to produce a long
@param val is the String to decode
@return the decode long
Ghidra/Features/BSim/src/main/java/ghidra/features/bsim/query/elastic/Base64Lite.java