def expanded_library_names
      library_names.map do |libname|
        pathname = File.expand_path(File.join(Libyajl2.opt_path, libname))
        pathname if File.file?(pathname)
      end.compact
    end
def expanded_library_names
      library_names.map do |libname|
        pathname = File.expand_path(File.join(Libyajl2.opt_path, libname))
        pathname if File.file?(pathname)
      end.compact
    end
Array of yajl library names prepended with the libyajl2 path to use to
 load those directly and bypass the system libyajl by default.  Since
 these are full paths, this API checks to ensure that the file exists on
 the filesystem.  May return an empty array.

 @api private
 @return [Array<String>] Array of full paths to libyajl2 gem libraries