arn: ARN{
				Partition:    "minio",
				Service:      "iam",
				Region:       "us-east-1",
				ResourceType: "role",
				ResourceID:   "my-role",
			},
			want: "arn:minio:iam:us-east-1::role/my-role",
		},
		{
			arn: ARN{
				Partition:    "minio",
				Service:      "",
				Region:       "us-east-1",
				ResourceType: "role",
				ResourceID:   "my-role",
			},
			want: "arn:minio::us-east-1::role/my-role",
		},

		Region:       serverRegion,
		ResourceType: arnResourceTypeRole,
		ResourceID:   resourceID,
	}, nil
}

// String - returns string representation of the ARN.
func (arn ARN) String() string {
	return strings.Join(
		[]string{
			arnPrefixArn,
			arn.Partition,
			arn.Service,
			arn.Region,
			"", // account-id is always empty in this implementation
			arn.ResourceType + "/" + arn.ResourceID,
		},
		":",
	)