public static void encodeLongBase64Padded(StringBuilder buf,long val) {
    	for(int i=60;i>=0;i-=6) {
    		int chunk = (int)(val >> i) & 0x3f;
    		buf.append(encode[chunk]);
    	}
    }
Encode a long value in base64 to the StringBuilder "stream" padding out with 'A' characters
so that exactly 11 characters are always written to the stream
@param buf is the buffer to write to
@param val is the long value to encode
Ghidra/Features/BSim/src/main/java/ghidra/features/bsim/query/elastic/Base64Lite.java