new

# File lib/rexml/source.rb, line 161
    def initialize(arg, block_size=500, encoding=nil)
      @er_source = @source = arg
      @to_utf = false
      @pending_buffer = nil

      if encoding
        super("", encoding)
      else
        super(@source.read(3) || "")
      end

      if !@to_utf and
          @buffer.respond_to?(:force_encoding) and
          @source.respond_to?(:external_encoding) and
          @source.external_encoding != ::Encoding::UTF_8
        @force_utf8 = true
      else
        @force_utf8 = false
      end
    end