You are an expert in writing code in many different languages. Your goal is to perform code completion for the following code, keeping in mind the rest of the code and the file meta data.
    Metadata details:
    filename: resolver.rb
    path of file: ./repos/travis-build/lib/travis/services/vault/keys
    
    the code of the file until where you have to start completion: require 'active_support/core_ext/object/blank'
require 'active_support/core_ext/string/inflections'

module Travis
  module Vault
    class Keys
      class Resolver
        ENV_NAME_REGEX = /^[a-zA-Z_][a-zA-Z0-9_]*$/.freeze

        attr_reader :paths, :version, :appliance

        delegate :data, to: :appliance
        delegate :vault, to: :appliance
        delegate :export, :echo, to: :'appliance.sh'

        def initialize(paths, version, appliance)
          @paths = paths
          @version = version
          @appliance = appliance
        end

        def call
          return if paths.blank?

          vault_secrets = []

          paths.each do |path|
            secret_data = Keys.const_get(version.upcase).resolve(path, vau
    
        def call
          return if paths.blank?

          vault_secrets = []

          paths.each do |path|
            secret_data = Keys.const_get(version.upcase).resolve(path, vault)
            if secret_data.present?
              secret_name = path.split('/').last
              secret_data.each do |key, value|
                env_name = key
                env_name = [secret_name, env_name].join('_') if true # To-Do: Make the prepend customizable from .travis.yml
                env_name = (path.split('/') << env_name).join('_') if false # To-Do: Make the prepend customizable from .travis.yml
                if env_name.match?(ENV_NAME_REGEX)
                  export(env_name.upcase, %("#{value}"), echo: false, secure: true)
                  vault_secrets << value
                else
                  echo *warn_message("The env name #{env_name} is invalid. Valid chars: a-z, A-Z, 0-9 and _. May NOT begin with a number.")
                end
              end
            else
              echo *warn_message("The value fetched for #{path} is blank.")
            end