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: file_path.rb
    path of file: ./repos/brakeman/lib/brakeman
    
    the code of the file until where you have to start completion: require 'pathname'

module Brakeman
  # Cl
    
    def self.from_app_tree app_tree, path
      return path if path.is_a? Brakeman::FilePath

      absolute = app_tree.expand_path(path).freeze

      if fp = @cache[absolute]
        return fp
      end