parameters: (self, handler)
docstring: Call handler for all pending reqs.
  
          :param handler: Handle a single requirement. Should take a requirement
              to install. Can optionally return an iterable of additional
              InstallRequirements to cover.
docstring_summary: Call handler for all pending reqs.
docstring_tokens: Call handler for all pending reqs .
function: def _walk_req_to_install(self, handler):
          """Call handler for all pending reqs.
  
          :param handler: Handle a single requirement. Should take a requirement
              to install. Can optionally return an iterable of additional
              InstallRequirements to cover.
          """
          # The list() here is to avoid potential mutate-while-iterating bugs.
          discovered_reqs = []
          reqs = itertools.chain(
              list(self.unnamed_requirements), list(self.requirements.values()),
              discovered_reqs)
          for req_to_install in reqs:
              more_reqs = handler(req_to_install)
              if more_reqs:
                  discovered_reqs.extend(more_reqs)
function_tokens: def _walk_req_to_install ( self , handler ) : # The list() here is to avoid potential mutate-while-iterating bugs. discovered_reqs = [ ] reqs = itertools . chain ( list ( self . unnamed_requirements ) , list ( self . requirements . values ( ) ) , discovered_reqs ) for req_to_install in reqs : more_reqs = handler ( req_to_install ) if more_reqs : discovered_reqs . extend ( more_reqs )