No vertices:
( )

One vertex:
( 0 )

Directed disconnected graph with loops and multiple edges, no weights, k = 0, IGRAPH_IN:
( 1 2 1 2 2 0 )

Same graph, k=1:
( 2 2 2 3 2 0 )

Same graph, without loops, k=1:
( 2 1 2 2 2 0 )

Same graph with loop, k=1, undirected:
( 4 3 3 5 2 0 )

Checking if calling igraph_local_scan_1_ecount properly redirects:
( 4 3 3 5 2 0 )

Same graph, directed, k=2:
( 2 4 2 6 5 0 )

Same graph, undirected, k=2:
( 6 8 8 8 5 0 )

Same graph, weighted:
( 0.9 2 2 2 1.8 0 )

Wrong size weights.
Negative k.