code: def _compute_dependencies(self):
          
          dm = self.__dep_map = {None: []}
  
          reqs = []
          # Including any condition expressions
          for req in self._parsed_pkg_info.get_all('Requires-Dist') or []:
              reqs.extend(parse_requirements(req))
  
          def reqs_for_extra(extra):
              for req in reqs:
                  if not req.marker or req.marker.evaluate({'extra': extra}):
                      yield req
  
          common = frozenset(reqs_for_extra(None))
          dm[None].extend(common)
  
          for extra in self._parsed_pkg_info.get_all('Provides-Extra') or []:
              s_extra = safe_extra(extra.strip())
              dm[s_extra] = list(frozenset(reqs_for_extra(extra)) - common)
  
          return dm
docs: Recompute this distribution's dependencies.