Class Diagram to be visualized on: http://yuml.me/diagram/scruffy/class/draw

[superCorpus]->[subCorpus2]
[subCorpus2]->[doc3]
[subCorpus2]->[doc4]
[superCorpus]->[subCorpus1]
[subCorpus1]->[doc1]
[subCorpus1]->[doc2]
