code: def supported_types_for_region(region_code):
      
      if not _is_valid_region_code(region_code):
          return set()
      metadata = PhoneMetadata.metadata_for_region(region_code.upper())
      return _supported_types_for_metadata(metadata)
docs: Returns the types for a given region which the library has metadata for.
  
      Will not include FIXED_LINE_OR_MOBILE (if numbers in this region could
      be classified as FIXED_LINE_OR_MOBILE, both FIXED_LINE and MOBILE would
      be present) and UNKNOWN.
  
      No types will be returned for invalid or unknown region codes.