<SYSTEM_TASK:>
Solve the following problem using Python, implementing the functions described below, one line at a time
<END_TASK>
<USER_TASK:>
Description:
 def layers(self):
 """Return a list of layers available. :return: List of layers available in the datastore. :rtype: list .. versionadded:: 4.0 """

        extensions = ['*.%s' % f for f in EXTENSIONS]
        self.uri.setNameFilters(extensions)
        files = self.uri.entryList()
        self.uri.setNameFilters([])
        files = human_sorting([QFileInfo(f).baseName() for f in files])
        return files