code: def supported_cache_type(types):
      
      if isinstance(types, str):
          types = [typ.strip() for typ in types.split(",")]
      for typ in types:
          if typ not in ["reflink", "hardlink", "symlink", "copy"]:
              return False
      return True
docs: Checks if link type config option has a valid value.
  
      Args:
          types (list/string): type(s) of links that dvc should try out.