public IEdge AddEdge(IEdge edge)
{
if (edge == null)
{
throw new ArgumentNullException(nameof(edge));
}
if (!Equals(edge.Parent) && !SubGraphs.ContainsKey(edge.Parent))
{
throw new ArgumentException(FormattableString.Invariant($"Parent of Edge {edge} not within Graph!"));
}
if ((edge.SourceNode == null) || !Nodes.ContainsKey(edge.SourceNode))
{
throw new ArgumentException(
FormattableString.Invariant($"SourceNode {edge.SourceNode} not within Graph!"));
}
if ((edge.EndNode == null) || !Nodes.ContainsKey(edge.EndNode))
{
throw new ArgumentException(FormattableString.Invariant($"EndNode {edge.EndNode} not within Graph!"));
}
if (!Edges.ContainsKey(edge))
{
Edges[edge] = edge;
}
var addedEdge = Edges[edge];
addedEdge.SetAttributes(edge.GetAttributes());
return(addedEdge);
}
