in src/app/agile-board-model.js [6:18]
function getIssuesAmountPerColumn(sprint, columnId) {
const concatArrays = (array1, array2) => array1.concat(array2);
const rows = concatArrays(
sprint.swimlanes || [], sprint.orphanRow || []
);
return rows.
map(row => row.cells || []).
reduce(concatArrays, []).
filter(cell => cell.column.id === columnId).
map(cell => cell.issues).
reduce(concatArrays, []).length;
}