code: static AxesWalker loadOneWalker(
            WalkingIterator lpi, Compiler compiler, int stepOpCodePos)
              throws javax.xml.transform.TransformerException
    {
  
      AxesWalker firstWalker = null;
      int stepType = compiler.getOp(stepOpCodePos);
  
      if (stepType != OpCodes.ENDOP)
      {
  
        // m_axesWalkers = new AxesWalker[1];
        // As we unwind from the recursion, create the iterators.
        firstWalker = createDefaultWalker(compiler, stepType, lpi, 0);
  
        firstWalker.init(compiler, stepOpCodePos, stepType);
      }
  
      return firstWalker;
    }
docs: This method is for building an array of possible levels
  where the target element(s) could be found for a match.
  @param lpi The owning location path iterator.
  @param compiler non-null reference to compiler object that has processed
  the XPath operations into an opcode map.
  @param stepOpCodePos The opcode position for the step.
  
  @return non-null AxesWalker derivative.
  
  @throws javax.xml.transform.TransformerException
  @xsl.usage advanced