docs: public static StaticBuffer padBuffer(StaticBuffer b, int length) {
          if (b.length()>=length) return b;
          byte[] data = new byte[length]; //implicitly initialized to all 0s
          for (int i = 0; i < b.length(); i++) {
              data[i]=b.getByte(i);
          }
          return new StaticArrayBuffer(data);
      }