# File temp/source.rb, line 134
                def initialize(arg, block_size=500, encoding=nil)
                        @er_source = @source = arg
                        @to_utf = false
      # Determining the encoding is a deceptively difficult issue to resolve.
      # First, we check the first two bytes for UTF-16.  Then we
      # assume that the encoding is at least ASCII enough for the '>', and
      # we read until we get one of those.  This gives us the XML declaration,
      # if there is one.  If there isn't one, the file MUST be UTF-8, as per
      # the XML spec.  If there is one, we can determine the encoding from
      # it.
      @buffer = ""
      str = @source.read( 2 )
      if encoding
        self.encoding = encoding
      elsif /\A(?:\xfe\xff|\xff\xfe)/n =~ str
        self.encoding = check_encoding( str )
      else
        @line_break = '>'
      end
      super str+@source.readline( @line_break )
    end