in pkg/conn/conn.go [295:305]
func getSTSRegionalEndpoint(r string) string {
p := getPartition(r)
var e string
if p == endpoints.AwsPartitionID || p == endpoints.AwsUsGovPartitionID {
e = STSEndpointPrefix + r + STSEndpointSuffix
} else if p == endpoints.AwsCnPartitionID {
e = STSEndpointPrefix + r + STSAwsCnPartitionIDSuffix
}
return e
}