Avoid processing empty labels.  This seems like the right thing, especially since if any subgraph has a label, the root graph gets a label of "" and then so do all other subgraphs that don't explicitly have a label. Because of the PAD macro, empty labels take up non-zero space. I hope there is not some user relying on this mechanism for adding some space.
Avoid processing empty labels.  This seems like the right thing, especially
since if any subgraph has a label, the root graph gets a label of "" and then
so do all other subgraphs that don't explicitly have a label.
Because of the PAD macro, empty labels take up non-zero space. I hope there is
not some user relying on this mechanism for adding some space.

kbrock/graphviz,pixelglow/graphviz,jho1965us/graphviz,ellson/graphviz,ellson/graphviz,tkelman/graphviz,kbrock/graphviz,BMJHayward/graphviz,jho1965us/graphviz,jho1965us/graphviz,tkelman/graphviz,jho1965us/graphviz,pixelglow/graphviz,BMJHayward/graphviz,kbrock/graphviz,tkelman/graphviz,MjAbuz/graphviz,MjAbuz/graphviz,BMJHayward/graphviz,MjAbuz/graphviz,tkelman/graphviz,MjAbuz/graphviz,pixelglow/graphviz,ellson/graphviz,kbrock/graphviz,ellson/graphviz,jho1965us/graphviz,tkelman/graphviz,jho1965us/graphviz,pixelglow/graphviz,BMJHayward/graphviz,pixelglow/graphviz,kbrock/graphviz,MjAbuz/graphviz,MjAbuz/graphviz,BMJHayward/graphviz,pixelglow/graphviz,tkelman/graphviz,tkelman/graphviz,MjAbuz/graphviz,MjAbuz/graphviz,pixelglow/graphviz,BMJHayward/graphviz,MjAbuz/graphviz,BMJHayward/graphviz,tkelman/graphviz,ellson/graphviz,BMJHayward/graphviz,pixelglow/graphviz,pixelglow/graphviz,tkelman/graphviz,BMJHayward/graphviz,ellson/graphviz,ellson/graphviz,jho1965us/graphviz,tkelman/graphviz,ellson/graphviz,kbrock/graphviz,ellson/graphviz,kbrock/graphviz,kbrock/graphviz,ellson/graphviz,kbrock/graphviz,ellson/graphviz,jho1965us/graphviz,BMJHayward/graphviz,tkelman/graphviz,kbrock/graphviz,pixelglow/graphviz,kbrock/graphviz,MjAbuz/graphviz,MjAbuz/graphviz,jho1965us/graphviz,BMJHayward/graphviz,pixelglow/graphviz,jho1965us/graphviz,jho1965us/graphviz