def read_json_escape_char
      str = @reader.read
      str += @reader.read
      str += @reader.read
      str += @reader.read
      if RUBY_VERSION >= '1.9'
        str.hex.chr(Encoding::UTF_8)
      else
        str.hex.chr
      end
    end
def read_json_escape_char
      str = @reader.read
      str += @reader.read
      str += @reader.read
      str += @reader.read
      if RUBY_VERSION >= '1.9'
        str.hex.chr(Encoding::UTF_8)
      else
        str.hex.chr
      end
    end
Decodes the four hex parts of a JSON escaped string character and returns
 the character via out.

 Note - this only supports Unicode characters in the BMP (U+0000 to U+FFFF);
 characters above the BMP are encoded as two escape sequences (surrogate pairs),
 which is not yet implemented