code: function removeEdge(vertex, edge) {
    var adj = vertex.adjacent
    var idx = elist.index(adj, edge)
    adj.splice(idx, 1)
    //Check if flag needs to be updated
    if(!((idx < adj.length && adj[idx].level === edge.level) ||
         (idx > 0 && adj[idx-1].level === edge.level))) {
      vertex.euler[edge.level].setFlag(false)
    }
  }
docs: Remove edge from list and update flags