def METHOD_NAME(self):
    self.data.tl.find_marker_genes(cluster_res_key='leiden', sort_by="log2fc",
                                   output=TEST_DATA_PATH + "/marker_genes2.csv")
    self.data.plt.marker_gene_volcano(group_name='2.vs.rest', vlines=False,
                                      out_path=TEST_IMAGE_PATH + "marker_gene_volcano.png")