The getCell operation will return a single element array containing the specified cell and its value.
// Initialize SheetSearch
var sheet = new x_vivid_sheets.SheetSearch('a5431dcc1b580210cf82ece03d4bzbab');
// Call getCell with the cell key you're looking for
var cell = sheet.getCell('B3');
// Return value is: [{"cell":"B3","value":859}]
gs.info(JSON.stringify(cell));