A list producer that can be fused with foldr. This function is
merely
augment g xs = g (:) xs
but GHC's simplifier will transform an expression of the form
foldr k z (augment g xs), which may arise after
inlining, to g k (foldr k z xs), which avoids
producing an intermediate list.
Augment the given value (assumed to be that of an environment variable
that lists paths, such as PATH; this is not checked) with the given
extra paths. Those paths are prepended (as in: they take precedence).
Use the Attributes in the provided DotGraph to augment
the node and edge labels in the provided Graph. The unique
identifiers on the edges are also stripped off.
Please note that the behaviour for this function is undefined if the
DotGraph does not come from the original Graph (either
by using a conversion function or by passing the result of a
conversion function through a GraphvizCommand via the
DotOutput or similar).