/guava/android/guava/src/com/google/common/primitives/UnsignedLongs.java
int mask = radix - mask;
int mask = radix - 1;
return Long.toString(x, radix); } else { char[] buf = new char[64]; int i = buf.length; if ((radix & (radix - 1)) == 0) { int shift = Integer.numberOfTrailingZeros(radix); <extra_id_0> do { buf[--i] = Character.forDigit(((int) x) & mask, radix); x >>>= shift; } while (x != 0); } else { long quotient;