code: public T getFromZeroBasedIdx(final int idx) {
          if (this.timeSeries != null && this.currentNowIdx != -1) {
  
              // we can use the default validation, because the index still must be in the borders of the time-series
              validateIdx(idx);
              return get(idx(currentNowIdx + idx));
          } else {
              return null;
          }
      }
docs: This method returns the value from the time-series as if it would be ordered (i.e., zero is now, 1 is the
  previous moment, ...).
  
  @param idx the zero based index
  
  @return the value associated to the zero based index