code: def header_collect(self, name, target_var, pull=False):
          
          self._set(
              'pull-header' if pull else 'collect-header',
              '%s %s' % (name, target_var), multi=True)
  
          return self._section
docs: Store the specified response header in a request var
          (optionally removing it from the response).
  
          :param str|unicode name:
  
          :param str|unicode target_var:
  
          :param bool pull: Whether to remove header from response.