func NewChainAlgorithm() *rank.AlgorithmChain {
	return rank.NewAlgorithmChain()
}
NewChainAlgorithm function retrieves an Algorithm object. It defines how
should work the text ranking algorithm, the weighting. This is an alternative
way to ranking words by weighting the number of the words. Because Algorithm
is an interface it's possible to modify the ranking algorithm by inject
different implementation. This is  the 4th step to use TextRank.
package textrank
import (
	"github.com/DavidBelicza/TextRank/v2/convert"
	"github.com/DavidBelicza/TextRank/v2/parse"
	"github.com/DavidBelicza/TextRank/v2/rank"
)
type TextRank struct {
	rank *rank.Rank
}
func NewTextRank() *TextRank {
	return &TextRank{
		rank.NewRank(),
	}
}
func NewDefaultRule() *parse.RuleDefault {
	return parse.NewRule()
}
func NewDefaultLanguage() *convert.LanguageDefault {
	return convert.NewLanguage()
}
func NewDefaultAlgorithm() *rank.AlgorithmDefault {
	return rank.NewAlgorithmDefault()
}