public void storeOn(Appendable appendable) {
PrintOn p = new PrintOn(appendable);
p.p("{\"n\":").p(rowCount()).p(",\"m\":").p(columnCount()).p(",\"data\":[");
for (Vector row: rows()) {
p.separatedBy(",").p("[");
PrintOn pp = new PrintOn(p);
for (Entry each: row.entries()) pp.separatedBy(",").p(each.value);
p.p("]");
}
p.p("]}");