def add_child(self, child):
        """ Adds a child to the CitationSet

        :param child: Child citation to add
        :return:
        """
        if isinstance(child, BaseCitation):
            self._children.append(child)
def add_child ( self , child ) : if isinstance ( child , BaseCitation ) : self . _children . append ( child )
Adds a child to the CitationSet

        :param child: Child citation to add
        :return: