def get_upregulated_genes(self) -> VertexSeq:
        """Get genes that are up-regulated.

        :return: Up-regulated genes.
        """
        up_regulated = self.graph.vs.select(self._is_upregulated_gene)
        logger.info(f"No. of up-regulated genes after laying on network: {len(up_regulated)}")
        return up_regulated
Get genes that are up-regulated.

        :return: Up-regulated genes.