Frequently used Jenkins code blocks configured in my Espanso https://espanso.org file.

matches:
  - trigger: :sign
    replace: |
      Regards,
      Your Signature

:jenfile

Jenkins declarative pipeline block

pipeline {
  agent any

  stages {
    stage("Stage 1") {
      echo 'Hello, world!'
    }
  }
}

:jendocker

Jenkins docker agent block

agent {
  docker {
    image 'python'
    reuseNode true
  }
}