Can I use jenkins post step from inside a shared library?

Question

In a shared library method I'm trying to execute a stage and a post step afterwards:

def call(String name = 'human') {
  echo "Hello, ${name}."
  this.stage("mystage"){
    this.node('master') {
      this.sh('echo executing stage')
    }
  }
  this.post {
    failure {
      echo 'This step failed!'
    }
  }
}

It gives an error No such DSL method 'post' found among steps. The post step can be used fine in a "normal" pipeline script like this: https://jenkins.io/doc/book/pipeline/syntax/#post

Is there a way to use it inside a shared library?

Cheers!