code: public long getUniqueValue() /*const*/ {
          int pos=pos_;
          if(pos<0) {
              return 0;
          }
          // Skip the rest of a pending linear-match node.
          long uniqueValue=findUniqueValue(chars_, pos+remainingMatchLength_+1, 0);
          // Ignore internally used bits 63..33; extend the actual value's sign bit from bit 32.
          return (uniqueValue<<31)>>31;
      }
docs: Determines whether all strings reachable from the current state
  map to the same value, and if so, returns that value.
  @return The unique value in bits 32..1 with bit 0 set,
  if all strings reachable from the current state
  map to the same value; otherwise returns 0.