def append(self, child):
        """
        Append the given child

        :class:`Element <hl7apy.core.Element>`
        :param child: an instance of an :class:`Element <hl7apy.core.Element>` subclass
        """
        if self._can_add_child(child):
            if self.element == child.parent:
                self._remove_from_traversal_index(child)
                self.list.append(child)
                try:
                    self.indexes[child.name].append(child)
                except KeyError:
                    self.indexes[child.name] = [child]
            elif self.element == child.traversal_parent:
                try:
                    self.traversal_indexes[child.name].append(child)
                except KeyError:
                    self.traversal_indexes[child.name] = [child]
Append the given child

        :class:`Element <hl7apy.core.Element>`
        :param child: an instance of an :class:`Element <hl7apy.core.Element>` subclass