pear/Image_GraphViz — pull request #3 by mcclimont (2014-04-23 05:19:34+00:00)
Title: Support for specifying default attributes defined by using a node, edge,...

... or graph statement,

where any object of the appropriate type will inherit this attribute value.

Reference: The DOT Language (http://www.graphviz.org/content/dot-language) under Lexical and Semantic Notes.