Jenkins shared library input example

shared_lib.groovy

// src/com/example/Helper.groovy
#!/usr/bin/env groovy
package com.example

class Helper implements Serializable {
    def context
    Helper(context) {
        this.context = context
    }
    
    def getUserInput(script) {
        // Following didnt' work.
        def ANSWER = context.input(message: 'Please provide parameters', ok: 'Next', 
            parameters: context.choice(name: 'ANSWER', choices: ['yes', 'no'].join('\n'), description: 'Select Answer?'))
        
        // Tried following, this also didn't work
        //def ANSWER = input(message: 'Please provide parameters', ok: 'Next', 
        //    parameters: choice(name: 'ANSWER', choices: ['yes', 'no'].join('\n'), description: 'Select Answer?'))
        
        // Tried following, this also didn't work
        //def ANSWER = script.input(message: 'Please provide parameters', ok: 'Next', 
        //    parameters: script.choice(name: 'ANSWER', choices: ['yes', 'no'].join('\n'), description: 'Select Answer?'))
      
       return ANSWER
    }
}

// Used the above class as in the Jenkinsfile
import com.example
def helper = new Helper(this);
pipeline {
  stages {
      stage("UserInputs") {
           steps {
                script { 
                    env.ANSWER=helper.getAnswer(env)
                }
            } 
      }
  }
}
// --------------- Helper.groovy ends -----------

// var/getAnswer.groovy

def call() {
  def ANSWER = input(message: 'Please provide parameters', ok: 'Next', 
            parameters: choice(name: 'ANSWER', choices: ['yes', 'no'].join('\n'), description: 'Select Answer?'))
  return ANSWER
}

// Used it as below in Jenkins file, this also didn't work

pipeline {
  stages {
      stage("UserInputs") {
           steps {
                script { 
                    env.ANSWER = getAnswer()
                }
            } 
      }
  }
}

// ------ getAnswer.groovyy ends here -----------