DocumentsQuery
Description:
Creates a new DocumentsQuery with its 
      q property set to q.
Parameters:
| q | 
           a query string, or   | 
      
Returns:
| 
           a new DocumentsQuery  | 
      
Creates a new DocumentsQuery with its 
      q property set to q.
| q | 
           a query string, or   | 
      
| 
           a new DocumentsQuery  |