sinterface IByteMemory64 {
  byte getByte(long idx);
  int getInt(long idx);
  //void setByte(long idx, byte val);
  long size();
  
  default int[] readIntArray(long start, int len) {
    int[] a = new[len];
    for i to len:
      a[i] = getInt(start+(((long) i) << 2));
    ret a;
  }
  
  default int[] readIntArray(LongRange r) {
    ret r == null ? null : readIntArray(r.start, toInt(r.length()));
  }
  
  default long getLong(long idx) {
    ret twoIntsToLong(getInt(idx), getInt(idx+4));
  }
  
  /*default void setLong(long idx, long val) {
    setInt(idx, firstIntFromLong(val));
    setInt(idx+4, secondIntFromLong(val));
  }*/
}

Began life as a copy of #1029375