anchor.diff:      }
     }
   
  -  _prefix = bytes[OID_LENGTH - 1] & 0x1f;
  -  _prefixEnd = min((bytes[OID_LENGTH] & 0x1f) + _prefix + 5,
  -      _CC_RANGE - 1);
  +  _prefix = min(bytes[OID_LENGTH - 1] & 0x3f, _CC_RANGE - 1);
  +  _prefixEnd = min(max(bytes[OID_LENGTH] & 0x3f, _prefix + 3), _CC_RANGE - 1);
   
     bytes.removeRange(OID_LENGTH - 1, _CHAR_PER_INT * _INT_LEN);
     for (int i = OID_LENGTH - 1; --i >= 0;)
  
positive.code: //OID is 24 chars (23 random number + 1 random sequential number) > 63^23 = 2.4e41
  //so it is about 10K more than 128 bit UUID (where 122 is effective: 5.3e36)
  //(note: Git revision is 2^40 about 1.46e48)
  
  /** The type of random generator
   *
  
negative.code: // Author: tomyeh
  library entity.oid;
  
  import "dart:math" show Random, min, max;
  
  //Note: we use characters a-z, A-Z, 0-9 and _, s.t., the user  can select all
  //by double-clicking it (they also valid characters no need of escapes).
  