Initializes the object formats tree.

        :param theme: Theme.
        :type theme: dict

def __initialize_tree(self, theme):
        """
        Initializes the object formats tree.

        :param theme: Theme.
        :type theme: dict
        """

        for item in sorted(theme):
            current_node = self.__root_node
            for format in item.split("."):
                nodes = [node for node in current_node.children if node.name == format]
                format_node = foundations.common.get_first_item(nodes)
                if not format_node:
                    format_node = FormatNode(format, format=theme[item])
                    current_node.add_child(format_node)
                current_node = format_node