code: def _get_cached_requirements(requirements, saltenv):
      '''
      Get the location of a cached requirements file; caching if necessary.
      '''
  
      req_file, senv = salt.utils.url.parse(requirements)
      if senv:
          saltenv = senv
  
      if req_file not in __salt__['cp.list_master'](saltenv):
          # Requirements file does not exist in the given saltenv.
          return False
  
      cached_requirements = __salt__['cp.is_cached'](
          requirements, saltenv
      )
      if not cached_requirements:
          # It's not cached, let's cache it.
          cached_requirements = __salt__['cp.cache_file'](
              requirements, saltenv
          )
      # Check if the master version has changed.
      if __salt__['cp.hash_file'](requirements, saltenv) != \
              __salt__['cp.hash_file'](cached_requirements, saltenv):
          cached_requirements = __salt__['cp.cache_file'](
              requirements, saltenv
          )
  
      return cached_requirementf _get_cached_requirements(requirements, saltenv):
      '''
      Get the location of a cached requirements file; caching if necessary.
      '''
  
      req_file, senv = salt.utils.url.parse(requirements)
      if senv:
          saltenv = senv
  
      if req_file not in __salt__['cp.list_master'](saltenv):
          # Requirements file does not exist in the given saltenv.
          return False
  
      cached_requirements = __salt__['cp.is_cached'](
          requirements, saltenv
      )
      if not cached_requirements:
          # It's not cached, let's cache it.
          cached_requirements = __salt__['cp.cache_file'](
              requirements, saltenv
          )
      # Check if the master version has changed.
      if __salt__['cp.hash_file'](requirements, saltenv) != \
              __salt__['cp.hash_file'](cached_requirements, saltenv):
          cached_requirements = __salt__['cp.cache_file'](
              requirements, saltenv
          )
  
      return cached_requirements
docs: Get the location of a cached requirements file; caching if necessary.