@Override
            public Double next() {
                if (currOffset == index.denseSubspaceSize) {
                    currentBlock = blockIterator.next().cells;
                    currOffset = 0;
                }
                return currentBlock[currOffset++];
            }
Returns an iterator over the values of this tensor.
The iteration order is the same as for cellIterator.
vespajlib/src/main/java/com/yahoo/tensor/MixedTensor.java