Implement a filter to temporarily disable unilateral edges
In directed networks, a tie between two actors is unilateral when only one actor identifies the other as connected (i.e. friend, vote, etc). A unilateral tie is depicted as a ingle arc. These ties are considered weak, as opposed to reciprocal ties where both actors identify each other as connected.
This feature enables the user to have a directed network symmetrized by focusing only on the strong, reciprocal ties.