convert json to 2d array
function jsonArrayTo2D(arrayOfObjects){
let header = [],
AoA = [];
arrayOfObjects.forEach(obj => {
Object.keys(obj).forEach(key => header.includes(key) || header.push(key))
let thisRow = new Array(header.length);
header.forEach((col, i) => thisRow[i] = obj[col] || '')
AoA.push(thisRow);
})
AoA.unshift(header);
return AoA;
}