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: pghero.rb
    path of file: ./repos/pghero/lib
    
    the code of the file until where you have to start completion: # dependencies
require "active_support"

# stdlib
require "forwardable"

# methods
require_relative "pghero/methods/basic"
r
    
    def databases
      unless defined?(@databases)
        # only use mutex on initialization
        MUTEX.synchronize do
          # return if another process initialized while we were waiting
          return @databases if defined?(@databases)

          @databases = config["databases"].map { |id, c| [id.to_sym, Database.new(id, c)] }.to_h
        end
      end