Orthologous self-loop (aka buckle) will remove its incident node during orthology collapsing

[abargnesi]

If a statement captures an abundance orthologous to itself then the abundance node will be removed during orthology collapsing.

For example the statement p(PFM:"Chemokine Receptor Family") orthologous p(PFM:"Chemokine Receptor Family") will produce a self-loop edge. The orthology collapse algorithm collapses the orthologous term to the species target then removes the orthologous. Since they are the same the effect is the removal of the p(PFM:"Chemokine Receptor Family") node.

The algorithm should handle this case and not remove the orthologous node if it is also the species target node.