func (f *Flag) Name() string {
	if len(f.Long) > 0 {
		return "--" + f.Long
	}
	if len(f.Short) > 0 {
		return "-" + f.Short
	}
	return "<unspecified>"
}
Return the name of the flag preceding the right amount of dashes.
The long name is preferred. If no name has been specified, "<unspecified>"
will be returned.
package goptions
import (
	"fmt"
	"reflect"
	"strings"
)
type Flag struct {
	Short        string
	Long         string
	MutexGroups  []string
	Description  string
	Obligatory   bool
	WasSpecified bool
	value        reflect.Value
	optionMeta   map[string]interface{}
	DefaultValue interface{}
}