How to use the scour.scour.scourString function in scour

def test_raster_paths_local_absolute(self):
        with open('unittests/raster-formats.svg', 'r') as f:
            svg = f.read()

        # create a reference string by scouring the original file with relative links
        options = ScourOptions
        options.infilename = 'unittests/raster-formats.svg'
        reference_svg = scourString(svg, options)

        # this will not always create formally valid paths but it'll check how robust our implementation is
        # (the third path is invalid for sure because file: needs three slashes according to URI spec)
        svg = svg.replace('raster.png',
                          '/' + os.path.abspath(os.path.dirname(__file__)) + '\\unittests\\raster.png')
        svg = svg.replace('raster.gif',
                          'file:///' + os.path.abspath(os.path.dirname(__file__)) + '/unittests/raster.gif')
        svg = svg.replace('raster.jpg',
                          'file:/' + os.path.abspath(os.path.dirname(__file__)) + '/unittests/raster.jpg')

        svg = scourString(svg)

        self.assertEqual(svg, reference_svg,
                         "Raster images from absolute local paths not properly embedded.")

# create a reference string by scouring the original file with relative links
        options = ScourOptions
        options.infilename = 'unittests/raster-formats.svg'
        reference_svg = scourString(svg, options)

        # this will not always create formally valid paths but it'll check how robust our implementation is
        # (the third path is invalid for sure because file: needs three slashes according to URI spec)
        svg = svg.replace('raster.png',
                          '/' + os.path.abspath(os.path.dirname(__file__)) + '\\unittests\\raster.png')
        svg = svg.replace('raster.gif',
                          'file:///' + os.path.abspath(os.path.dirname(__file__)) + '/unittests/raster.gif')
        svg = svg.replace('raster.jpg',
                          'file:/' + os.path.abspath(os.path.dirname(__file__)) + '/unittests/raster.jpg')

        svg = scourString(svg)

        self.assertEqual(svg, reference_svg,
                         "Raster images from absolute local paths not properly embedded.")

def runTest(self):
        with open('unittests/newlines.svg') as f:
            s = scourString(f.read())
        self.assertEqual(len(s.splitlines()), 24,
                         'Did handle reading or outputting line ending characters correctly')

def runTest(self):
        with open('unittests/xml-ns-decl.svg') as f:
            xmlstring = scourString(f.read())
        self.assertTrue(xmlstring.find('xmlns:rdf="http://www.w3.org/1999/02/22-rdf-syntax-ns#"') != -1,
                        'Improperly serialized namespace prefix declarations when not in default namespace')

def test_scourString(self):
        options = ScourOptions
        try:
            scourString(self.MINIMAL_SVG, options)
            fail = False
        except Exception:
            fail = True
        self.assertEqual(fail, False,
                         'Exception when calling "scourString" with empty options object')

def runTest(self):
        with open('unittests/style-cdata.svg') as f:
            docStr = f.read()
        docStr = scourString(docStr,
                             parse_args(['--shorten-ids']))
        self.assertEqual(docStr.find('somethingreallylong'), -1,
                         'Did not shorten IDs in the internal stylesheet')

def runTest(self):
        with open('unittests/quotes-in-styles.svg', "rb") as f:
            output = scourString(f.read())
        self.assertTrue('use[id="t"]' in output,
                        'Failed to preserve quote characters in a style element')
        self.assertTrue("'Times New Roman'" in output,
                        'Failed to preserve quote characters in a style attribute')

def runTest(self):
        with open('unittests/cdata.svg') as f:
            lines = scourString(f.read()).splitlines()
        self.assertEqual(lines[3],
                         "  	alert('pb&j');",
                         'CDATA did not come out correctly')

def effect(self):
        try:
            input = file(self.args[0], "r")
            self.options.infilename = self.args[0]
            sys.stdout.write(scourString(input.read(), self.options).encode("UTF-8"))
            input.close()
            sys.stdout.close()
        except Exception as e:
            inkex.errormsg("Error during optimization.")
            inkex.errormsg("\nDetails:\n" + str(e))
            inkex.errormsg("\nOS version: " + platform.platform())
            inkex.errormsg("Python version: " + sys.version)
            inkex.errormsg("Scour version: " + scour.__version__)
            sys.exit()