Set edges/arc in the network.

        Parameters
        ----------
        edge_list: array_like
            list, tuple, dict or set whose each elements has two values (parent, child).

        Examples
        --------
        >>> from pgmpy.readwrite.XMLBeliefNetwork import XBNWriter
        >>> writer = XBNWriter()
        >>> writer.set_edges([('a', 'b'), ('a', 'c'), ('b', 'd'), ('c', 'd'), ('c', 'e')])

def set_edges(self, edge_list):
        """
        Set edges/arc in the network.

        Parameters
        ----------
        edge_list: array_like
            list, tuple, dict or set whose each elements has two values (parent, child).

        Examples
        --------
        >>> from pgmpy.readwrite.XMLBeliefNetwork import XBNWriter
        >>> writer = XBNWriter()
        >>> writer.set_edges([('a', 'b'), ('a', 'c'), ('b', 'd'), ('c', 'd'), ('c', 'e')])
        """
        structure = etree.SubElement(self.bnmodel, 'STRUCTURE')
        for edge in edge_list:
            etree.SubElement(structure, 'ARC', attrib={'PARENT': edge[0], 'CHILD': edge[1]})