/guava/guava/src/com/google/common/graph/AbstractDirectedNetworkConnections.java
N previousNode = outEdgeMap.remove( edge) ;N previousNode = inEdgeMap.remove( edge) ;
N previousNode = inEdgeMap.remove ( edge ) ;
} @Override public N removeInEdge(E edge, boolean isSelfLoop) { if (isSelfLoop) { checkNonNegative(--selfLoopCount); } <extra_id_0> return requireNonNull(previousNode); } @Override public N removeOutEdge(E edge) { N previousNode = outEdgeMap.remove(edge); return requireNonNull(previousNode);