Gets all of the variables or the specific variable. This is a paginated API. Providing null <code>maxSizePerPage</code> results in retrieving maximum of 100 records per page. If you provide <code>maxSizePerPage</code> the value must be between 50 and 100. To get the next page result, a provide a pagination token from <code>GetVariablesResult</code> as part of your request. Null pagination token fetches the records from the beginning.