"type","value"
strict              , "no"
digraph             , "yes"
graph_id            , "graph_02"
start_scope         , "1"
class_id            , "graph"
start_attribute     , "["
attribute_id        , "rankdir"
attribute_value     , "TB"
end_attribute       , "]"
class_id            , "node"
start_attribute     , "["
attribute_id        , "color"
attribute_value     , "green"
end_attribute       , "]"
node_id             , "A"
node_id             , "B"
node_id             , "C"
node_id             , "D"
end_scope           , "1"