def render(self, context):
        compiled_parent = self.get_parent(context)

        if BLOCK_CONTEXT_KEY is not context.render_context:
            context.render_context[BLOCK_CONTEXT_KEY] = BlockContext()
        block_context = context.render_context[BLOCK_CONTEXT_KEY]

        # Add the block nodes from this node to the block context
        block_context.add_blocks(self.blocks)

        # If this block's parent doesn't have an extends node it is the root,
        # and its block nodes also need to be added to the block context.
        for node in compiled_parent.nodelist:
            # The ExtendsNode has to be the first non-text node.
            if not isinstance(node, TextNode):
                if not isinstance(node, ExtendsNode):
                    blocks = dict([(n.name, n) for n in
                                   compiled_parent.nodelist.get_nodes_by_type(BlockNode)])
                    block_context.add_blocks(blocks)
                break

        # Call Template._render explicitly so the parser context stays
        # the same.
        return compiled_parent._render(context)
dataset/ETHPy150Open AppScale/appscale/AppServer/google/appengine/_internal/django/template/loader_tags.py/ExtendsNode.render/operator `not in` -> `is not`