void updateClusterXY(int cluster, Point2D pt) {
		int vertexList = getClusterVertices(cluster);
		for (int vh = m_cluster_vertices.getFirst(vertexList); vh != -1; vh = m_cluster_vertices
				.getNext(vh)) {
			int vertex = m_cluster_vertices.getElement(vh);
			m_shape.setXY(vertex, pt);
		}
	}
void updateClusterXY ( int cluster , Point2D pt ) { int vertexList = getClusterVertices ( cluster ) ; for ( int vh = m_cluster_vertices . getFirst ( vertexList ) ; vh != - 1 ; vh = m_cluster_vertices . getNext ( vh ) ) { int vertex = m_cluster_vertices . getElement ( vh ) ; m_shape . setXY ( vertex , pt ) ; } }
Updates all vertices of the cluster to new coordinate