code: def parse_at_root(
              self,
              root,  # type: ET.Element
              state  # type: _ProcessorState
      ):
          # type: (...) -> Any
          
          if not self._nested:
              raise InvalidRootProcessor('Non-nested array "{}" cannot be root element'.format(
                  self.alias))
  
          parsed_array = []  # type: List
  
          array_element = _element_find_from_root(root, self._nested)
          if array_element is not None:
              parsed_array = self.parse_at_element(array_element, state)
          elif self.required:
              raise MissingValue('Missing required array at root: "{}"'.format(self._nested))
  
          return parsed_array
docs: Parse the root XML element as an array.