read.go
func (v Value) Bool() bool {
	x, ok := v.data.(bool)
	if !ok {
		return false
	}
	return x
}
func (v Value) Bool() bool {
	x, ok := v.data.(bool)
	if !ok {
		return false
	}
	return x
}
// Bool returns v's boolean value.
// If v.Kind() != Bool, Bool returns false.