public Mutate deleteAll(String columnFamily) {
Deletion deletion = new Deletion();
deletion.setTimestamp(Long.MAX_VALUE); //TODO: check this
deletion.predicate = new SlicePredicate();
SliceRange sliceRange =
new SliceRange(new byte[0], new byte[0], false, Integer.MAX_VALUE);
deletion.predicate.slice_range = sliceRange;
Mutation mutation = new Mutation();
mutation.deletion = deletion;
addToMutationMap(columnFamily, mutation);
return this;