 public class LineageAlignment {
     
     public class Cell {
-        public internal(set) var offset: Int = 0
+        public internal(set) var offset: Int = -1
         public private(set) var node: LineageTree.Node
         
         init(node: LineageTree.Node) {

                var offset = x
                for endPoint in endPoints {
                    if endPoint === cell.node {
                        break
                    }
                    
                    if !column.participatesInLineageOf(endPoint) {
                        offset += 1
                    } else if !cell.node.isPresentInLineageOf(endPoint) {

                        cell.offset = offset
                        break
                    }
                }
                if cell.offset == -1 {
                    cell.offset = offset
                }
            }
        }
