function getAllTransactions (collection, allRequests) {
  if (!_.has(collection, 'item') || !_.isArray(collection.item)) {
    return;
  }
  _.forEach(collection.item, (item) => {
    if (_.has(item, 'request') || _.has(item, 'response')) {
      allRequests.push(item);
    }
    else {
      getAllTransactions(item, allRequests);
    }
  });
}
Extract all transaction from collection and appends them into array

@param {*} collection - Postman Collection
@param {*} allRequests - Array to which transactions are appended
@returns {*} - null