func (p *Points) Append(onePoint Point) *Points {
	p.Data = append(p.Data, onePoint)
	return p
}
func (p *Points) Append(onePoint Point) *Points {
	p.Data = append(p.Data, onePoint)
	return p
}
func ( p * Points ) Append ( onePoint Point ) * Points { p . Data = append ( p . Data , onePoint ) return p }
// Append point
Append point