tr: function(){
const elem = [];
for(let i = 1; i <= this.rows;i++){
elem.push(React.createElement('tr',{key: i.toString()},
function(){
let elem=[];
for(let i = 1; i <= this.rows;i++){
elem.push(React.createElement('td',{key: i.toString()}, i));
}
return elem;));
}
return elem;
}