func SetHeader(h map[string][]string) FileSetting {
	return func(f *file) {
		for k, v := range h {
			f.Header[k] = v
		}
	}
}
func SetHeader(h map[string][]string) FileSetting {
	return func(f *file) {
		for k, v := range h {
			f.Header[k] = v
		}
	}
}
func SetHeader ( h map [ string ] [ ] string ) FileSetting { return func ( f * file ) { for k , v := range h { f . Header [ k ] = v } } }
// SetHeader is a file setting to set the MIME header of the message part that
// contains the file content.
//
// Mandatory headers are automatically added if they are not set when sending
// the email.
SetHeader is a file setting to set the MIME header of the message part that contains the file content . Mandatory headers are automatically added if they are not set when sending the email .