Segment getSegment(int vertex) {
		if (m_segments != null) {
			int vindex = getVertexIndex(vertex);
			return m_segments.get(vindex);
		}
		return null;
	}
Segment getSegment ( int vertex ) { if ( m_segments != null ) { int vindex = getVertexIndex ( vertex ) ; return m_segments . get ( vindex ) ; } return null ; }
if it is a Line.