code: def search(self, q, field=None, page=None, per_page=None):
          
  
          def picker(results):
              if type(results['result']) == list:
                  return results['result']
              else:
                  return [results['result']]
  
          return self._get(('search',), picker, q=q, field=field, page=page, per_page=per_page)
docs: Search across all (without field) or in specific field
          (valid fields at http://www.loc.gov/standards/mods/mods-outline.html)