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Solve the following problem using Python, implementing the functions described below, one line at a time
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Description:
 def get_src_folder(self):
 """ Gets the app source folder from settings.gradle file. Returns: A string containing the project source folder name (default is "app") """

    with open('%s/settings.gradle' % self.path) as f:
      for line in f.readlines():
        if line.startswith('include'):
          matches = re.findall(r'\'\:?(.+?)\'', line)
        if len(matches) == 0:
          continue
        for folder in matches:
          if self.is_app_folder(folder):
            return folder
    return 'app'