**FastAPI** uses it so that, if you use a Pydantic model in `response_model`, and your data has an error, you will see the error in your log.

But the client/user will not see it. Instead, the client will receive an "Internal Server Error" with an HTTP status code `500`.

	// ErrSubQueryRequired sub query required
	ErrSubQueryRequired = errors.New("sub query required")
	// ErrInvalidData unsupported data
	ErrInvalidData = errors.New("unsupported data")
	// ErrUnsupportedDriver unsupported driver
	ErrUnsupportedDriver = errors.New("unsupported driver")
	// ErrRegistered registered
	ErrRegistered = errors.New("registered")

		if netErr, ok := err.(*net.OpError); ok {
			return ErrPortAccess(netErr).Msg("Insufficient permissions to use specified port")
		}
	}

	// Failed to identify what type of error this, return a simple UI error
	return Err{msg: err.Error()}
}

// FmtError converts a fatal error message to a more clear error
// using some colors
func FmtError(introMsg string, err error, jsonFlag bool) string {

var errDoneForNow = errors.New("done for now")

// errSkipFile returned by the fn() for readDirFn() when it needs
// to proceed to next entry.
var errSkipFile = errors.New("skip this file")

var errIgnoreFileContrib = errors.New("ignore this file's contribution toward data-usage")

// errXLBackend XL drive mode requires fresh deployment.
var errXLBackend = errors.New("XL backend requires fresh drive")

	}
)

// Error is a KMS error that can be translated into an S3 API error.
//
// It does not implement the standard error Unwrap interface for
// better error log messages.
type Error struct {
	Code    int    // The HTTP status code returned to the client
	APICode string // The API error code identifying the error
	Err     string // The error message returned to the client
	Cause   error  // Optional, lower level error cause.
}

}

// ErrInvalidFilterName - invalid filter name error.
type ErrInvalidFilterName struct {
	FilterName string
}

func (err ErrInvalidFilterName) Error() string {
	return fmt.Sprintf("invalid filter name '%v'", err.FilterName)
}

// ErrFilterNamePrefix - more than one prefix usage error.
type ErrFilterNamePrefix struct{}

func (err ErrFilterNamePrefix) Error() string {
	return "more than one prefix in filter rule"
}

	message    string
	statusCode int
	cause      error
}

func (err *s3Error) Cause() error {
	return err.cause
}

func (err *s3Error) ErrorCode() string {
	return err.code
}

func (err *s3Error) ErrorMessage() string {
	return err.message
}

func (err *s3Error) HTTPStatusCode() int {
	return err.statusCode
}

func (err *s3Error) Error() string {
	return err.message
}

	message    string
	statusCode int
	cause      error
}

func (err *s3Error) Cause() error {
	return err.cause
}

func (err *s3Error) ErrorCode() string {
	return err.code
}

func (err *s3Error) ErrorMessage() string {
	return err.message
}

func (err *s3Error) HTTPStatusCode() int {
	return err.statusCode
}

func (err *s3Error) Error() string {
	return err.message
}

package s3select

// /////////////////////////////////////////////////////////////////////
//
//	Validation errors.
//
// /////////////////////////////////////////////////////////////////////
func errExpressionTooLong(err error) *s3Error {
	return &s3Error{
		code:       "ExpressionTooLong",
		message:    "The SQL expression is too long: The maximum byte-length for the SQL expression is 256 KB.",

}

// toAPIErrorCode - Converts embedded errors. Convenience
// function written to handle all cases where we have known types of
// errors returned by underlying layers.
func toAPIErrorCode(ctx context.Context, err error) (apiErr APIErrorCode) {
	if err == nil {
		return ErrNone
	}

	// Errors that are generated by net.Conn and any context errors must be handled here.