    # File lib/RMagick.rb, line 863
        def get_exif_by_number(*tag)
            hash = Hash.new
            if tag.length == 0
                exif_data = self['EXIF:!']
                if exif_data
                    exif_data.split("\n").each do |exif|
                        tag, value = exif.split('=')
                        tag = tag[1,4].hex
                        hash[tag] = value
                    end
                end
            else
                get_exif_by_number()    # ensure properties is populated with exif data
                tag.each do |num|
                    rval = self['#%04X' % num.to_i]
                    hash[num] = rval == 'unknown' ? nil : rval
                end
            end
            return hash
        end