text: import os
  
  import yaml
  
  from .config_source import ConfigSource
  
  
  def yaml_include(loader, node):
      path = node.value
      if loader:
          path = os.path.join(os.path.dirname(loader.name), path)
      with open(path) as inputfile:
          return yaml.load(inputfile)
  
  yaml.add_constructor("!include", yaml_include)
  
  
  class YamlFileConfigSource(ConfigSource):
  
      def __init__(self, filename):
          self.filename = filename
  
      def get(self):
          return yaml.load(open(self.filename))
  