code: void insertOp(int pos, int length, int op)
    {
  
      int totalLen = m_ops.getOp(OpMap.MAPINDEX_LENGTH);
  
      for (int i = totalLen - 1; i >= pos; i--)
      {
        m_ops.setOp(i + length, m_ops.getOp(i));
      }
  
      m_ops.setOp(pos,op);
      m_ops.setOp(OpMap.MAPINDEX_LENGTH,totalLen + length);
    }
docs: Insert room for operation.  This will NOT set
  the length value of the operation, but will update
  the length value for the total expression.
  
  @param pos The position where the op is to be inserted.
  @param length The length of the operation space in the op map.
  @param op The op code to the inserted.