func (p *Parser) Consume() {
	p.ConsumeN(1)
}
Consume one token. It will be gone forever.
package pongo2
import (
	"fmt"
	"strings"
	"github.com/juju/errors"
)
type INode interface {
	Execute(*ExecutionContext, TemplateWriter) *Error
}
type IEvaluator interface {
	INode
	GetPositionToken() *Token
	Evaluate(*ExecutionContext) (*Value, *Error)
	FilterApplied(name string) bool
}
type Parser struct {
	name      string
	idx       int
	tokens    []*Token
	lastToken *Token
	template *Template
}
func newParser(name string, tokens []*Token, template *Template) *Parser {
	p := &Parser{
		name:     name,
		tokens:   tokens,
		template: template,
	}
	if len(tokens) > 0 {
		p.lastToken = tokens[len(tokens)-1]
	}
	return p
}