func (m MapClaims) VerifyNotBefore(cmp int64, req bool) bool {
	switch nbf := m["nbf"].(type) {
	case float64:
		return verifyNbf(int64(nbf), cmp, req)
	case json.Number:
		v, _ := nbf.Int64()
		return verifyNbf(v, cmp, req)
	}
	return req == false
}
Compares the nbf claim against cmp.
If required is false, this method will return true if the value matches or is unset
package jwt
import (
	"encoding/json"
	"errors"
)
type MapClaims map[string]interface{}
func (m MapClaims) VerifyAudience(cmp string, req bool) bool {
	aud, _ := m["aud"].(string)
	return verifyAud(aud, cmp, req)
}
func (m MapClaims) VerifyExpiresAt(cmp int64, req bool) bool {
	switch exp := m["exp"].(type) {
	case float64:
		return verifyExp(int64(exp), cmp, req)
	case json.Number:
		v, _ := exp.Int64()
		return verifyExp(v, cmp, req)
	}
	return req == false
}
func (m MapClaims) VerifyIssuedAt(cmp int64, req bool) bool {
	switch iat := m["iat"].(type) {
	case float64:
		return verifyIat(int64(iat), cmp, req)
	case json.Number:
		v, _ := iat.Int64()
		return verifyIat(v, cmp, req)
	}
	return req == false
}
func (m MapClaims) VerifyIssuer(cmp string, req bool) bool {
	iss, _ := m["iss"].(string)
	return verifyIss(iss, cmp, req)
}