public static bool Contains(this IArcs edge, INode node) => edge.From == node || edge.To == node;
public bool Equals(IArcs other) => ReferenceEquals(other, this) || other is not null && other.From == From && other.To == To;
public static bool Contains(this IArcs edge, INode node) => edge.From == node || edge.To == node;
public bool Equals(IArcs other) => ReferenceEquals(other, this) || other is not null && other.From == From && other.To == To;