Prepends a predecessor to the first node in this graph and makes that the first node.
Appends a successor to the last node in this graph and makes that the last node.
Appends one decomposition to another.
Appends one decomposition to another. The first node of this graph will be the first node of the result. The last node of the given graph will be the last node of the result. The given edge will be added from the last node of this graph to the first node of the given graph.
The decomposition of a graph into two detached contexts focused on distinguished "first" and "last" nodes.