 */
 public class AdjacencyMatrix<Vertex: Hashable> {
     /** The adjacency matrix itself.  */
-    private var matrix: Matrix<Int>
+    private var matrix: Matrix<Int8>
 
     /**
      A dictionary mapping vertices to their indices in the matrix.

    /**
     Creates an array of all vertices reachable from a vertex.

     A *default implementation* using `vertices` and `edgeExists` is provided.
     It works in O(V) time.

     - parameter vertex: The vertex whose neighbors to retrieve.

     - returns: An array of all vertices with edges from `vertex` to them, in no

    }

    /**
     Removes a given row from the matrix.

     - parameter row: The row to be removed.

     - returns: `Bit.One` if the row was in the matrix, or `.Zero` otherwise.

     - complexity: O(`nRows` * `nCols`)
    */
