code: public boolean canTraverseOutsideSubtree()
     {
       if(null != m_patterns)
       {
        int n = m_patterns.length;
        for (int i = 0; i < n; i++) 
        {
          if(m_patterns[i].canTraverseOutsideSubtree())
            return true;
        }
       }
       return false;
     }
docs: Tell if this expression or it's subexpressions can traverse outside
  the current subtree.
  
  @return true if traversal outside the context node's subtree can occur.