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: layer_mask.rb
    path of file: ./repos/psd.rb/lib/psd
    
    the code of the file until where you have to start completion: class PSD
  # Covers parsing the global ma
    
    def parse_additional_layer_info_block
      sig = @file.read_string(4)

      unless %w(8BIM 8B64).include?(sig)
        @file.seek(-4, IO::SEEK_CUR)
        return false
      end