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: from_configuration.rb
    path of file: ./repos/hexapdf/lib/hexapdf/font_loader
    
    the code of the file until where you have to start completion: # -*- encoding: utf-8; frozen_string_literal: true -*-
#
#--
# This file is part of HexaPDF.
#
# HexaPDF - A Versatile PDF Creation and Manipulation Library For 
    
      def self.call(document, name, variant: :none, subset: true)
        file = document.config['font.map'].dig(name, variant)
        return nil if file.nil?

        unless file.kind_of?(HexaPDF::Font::TrueType::Font) || File.file?(file)
          raise HexaPDF::Error, "The configured font file #{file} is not a valid value"
        end
        FromFile.call(document, file, subset: subset)
      end