def METHOD_NAME(self):
    getline = linecache.getline
    # Create a source file and cache its contents
    source_name = support.TESTFN + '.py'
    self.addCleanup(support.unlink, source_name)
    with open(source_name, 'w') as source:
        source.write(SOURCE_1)
    getline(source_name, 1)
    # Keep a copy of the old contents
    source_list = []
    with open(source_name) as source:
        for index, line in enumerate(source):
            self.assertEqual(line, getline(source_name, index + 1))
            source_list.append(line)
    with open(source_name, 'w') as source:
        source.write(SOURCE_2)
    # Try to update a bogus cache entry
    linecache.checkcache('dummy')
    # Check that the cache matches the old contents
    for index, line in enumerate(source_list):
        self.assertEqual(line, getline(source_name, index + 1))
    # Update the cache and check whether it matches the new source file
    linecache.checkcache(source_name)
    with open(source_name) as source:
        for index, line in enumerate(source):
            self.assertEqual(line, getline(source_name, index + 1))
            source_list.append(line)