public int assignIDs(int lastID){
  int currLastID=lastID + 1;
  m_id=currLastID;
  if (m_sons != null) {
    for (    LMTNode m_son : m_sons) {
      currLastID=m_son.assignIDs(currLastID);
    }
  }
  return currLastID;
}

public int assignIDs ( int lastID ) { int currLastID = lastID + 1 ; m_id = currLastID ; if ( m_sons != null ) { for ( LMTNode m_son : m_sons ) { currLastID = m_son . assignIDs ( currLastID ) ; } } return currLastID ; }
assigns unique ids to all nodes in the tree
