src/prompting-helper.js
function promptingHelper( generator, generator_prompts ) {
  var prompts = filterPrompts( generator.options.PromptAnswers, generator_prompts );

  return generator.prompt( prompts )
    .then(
      function ( answers ) {
        addPromptAnswers( generator.options.PromptAnswers, answers );
      }
    );
}
function promptingHelper( generator, generator_prompts ) {
  var prompts = filterPrompts( generator.options.PromptAnswers, generator_prompts );

  return generator.prompt( prompts )
    .then(
      function ( answers ) {
        addPromptAnswers( generator.options.PromptAnswers, answers );
      }
    );
}
function promptingHelper ( generator , generator_prompts ) { var prompts = filterPrompts ( generator . options . PromptAnswers , generator_prompts ) ; return generator . prompt ( prompts ) . then ( function ( answers ) { addPromptAnswers ( generator . options . PromptAnswers , answers ) ; } ) ; }
filters prompts for a generator

compares prompts in the provided generator_prompts with those in generator.options.PromptAnswers.
if a prompt.name already exists in generator.options.PromptAnswers.answers, then it’s not
presented again to the user. the generator can retrieve the previously answered prompt with
generator.options.PromptAnswers.get( prompt.name )

@param {Object} generator
@param {Array} generator_prompts
@returns {Promise}
filters prompts for a generator