code: private void move1() {
          if (node == null)
              return;
  
          if (position >= reference.size()) {
              node = null;
              return;
          }
  
          node = node.links[reference.codeAt(position++)];
      }
docs: Move the pointer one step forward. Move is made exactly matching the corresponding nucleotide in the reference
  sequence, so this method prevents branching in the current position.