digraph Perl
{
graph [ rankdir="TB" ]
node [ shape="oval" ]
edge [ color="grey" ]
"node.1" [ label="n 1" ]
"50" [ color="invis" label="" shape="point" width="0" ]
"" [ label="n 2" ]
"node.3" [ label="n 3" ]
"57" [ color="invis" label="" shape="point" width="0" ]
"43" [ color="invis" label="" shape="point" width="0" ]
"node.1" -> "50" [ label="e 1" ]
"50" -> "" [ label="e 2" ]
"" -> "node.3" [ label="e 3" ]
"node.3" -> "57" [ label="e 4" ]
"57" -> "" [ label="e 5" ]
"" -> "43" [ label="e 6" ]
}