func (f BoolTFlag) String() string {
	return FlagStringer(f)
}
String returns a readable representation of this value
(for usage defaults)
package cli
import (
	"flag"
	"strconv"
	"time"
)
type BoolFlag struct {
	Name        string
	Usage       string
	EnvVar      string
	Hidden      bool
	Destination *bool
}
func (f BoolFlag) String() string {
	return FlagStringer(f)
}
func (f BoolFlag) GetName() string {
	return f.Name
}
func (c *Context) Bool(name string) bool {
	return lookupBool(name, c.flagSet)
}
func (c *Context) GlobalBool(name string) bool {
	if fs := lookupGlobalFlagSet(name, c); fs != nil {
		return lookupBool(name, fs)
	}
	return false
}
func lookupBool(name string, set *flag.FlagSet) bool {
	f := set.Lookup(name)
	if f != nil {
		parsed, err := strconv.ParseBool(f.Value.String())
		if err != nil {
			return false
		}
		return parsed
	}
	return false
}
type BoolTFlag struct {
	Name        string
	Usage       string
	EnvVar      string
	Hidden      bool
	Destination *bool
}