code: func (m *Meta) configSources() map[string][]byte {
  	if m.configLoader == nil {
  		return nil
  	}
  
  	return m.configLoader.Sources()
  }
docs: // configSources returns the source cache from the receiver's config loader,
  // which the caller must not modify.
  //
  // If a config loader has not yet been instantiated then no files could have
  // been loaded already, so this method returns a nil map in that case.