code: private int findEndOfNowiki (int startBlock) {
          // NOTE: this method could step back one char from startBlock position
          int endBlock=startBlock-3;
          do {
              endBlock=wikiText.indexOf("}}}", endBlock+3);
              if (endBlock<0) return wikiLength; // no matching '}}}' found
              while (endBlock+3<wikiLength && wikiChars[endBlock+3]=='}')
                  endBlock++; // shift to end of sequence of more than 3x'}' (eg. '}}}}}')
          } while (wikiChars[endBlock-1]=='~');
          return endBlock;
      }
docs: Finds first closing '}}}' for nowiki block or span.
  Skips escaped sequences: '~}}}'.
  
  @param startBlock points to first char after '{{{'
  @return position of first '}' in closing '}}}'