func (f *StringFlag) IsRequired() bool {
	return f.Required
}
IsRequired returns whether or not the flag is required
package cli
import "flag"
type StringFlag struct {
	Name        string
	Aliases     []string
	Usage       string
	EnvVars     []string
	FilePath    string
	Required    bool
	Hidden      bool
	TakesFile   bool
	Value       string
	DefaultText string
	Destination *string
	HasBeenSet  bool
}
func (f *StringFlag) IsSet() bool {
	return f.HasBeenSet
}
func (f *StringFlag) String() string {
	return FlagStringer(f)
}
func (f *StringFlag) Names() []string {
	return flagNames(f.Name, f.Aliases)
}