.. graphviz:: myfile.dot
+See the `Dot User's Manual <https://www.graphviz.org/pdf/dotguide.pdf>`_ by
+Emden R. Gansner, Eleftherios Koutsofios, and Stephen North for examples of
+digraphs. This is especially useful if this is your first time encountering
+GraphViz.
Ditaa
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