def add_edge_from(self, from_dsa_dnstr):
        """Add an edge from the dsa to our graph nodes edge from list

        :param from_dsa_dnstr: the dsa that the edge emanates from
        """
        assert from_dsa_dnstr is not None

        # No edges from myself to myself
        if from_dsa_dnstr == self.dsa_dnstr:
            return False
        # Only one edge from a particular node
        if self.edge_from in from_dsa_dnstr:
            return False
        # Not too many edges
        if len(self.edge_from) >= self.max_edges:
            return False
        self.edge_from.append(from_dsa_dnstr)
        return True
dataset/ETHPy150Open byt3bl33d3r/pth-toolkit/lib/python2.7/site-packages/samba/kcc_utils.py/GraphNode.add_edge_from/swapped operands of `in`