code: def graphviz(self, directory, **kwargs):
          "Directory to store the graphviz models"
          import os
          if not os.path.isdir(directory):
              os.mkdir(directory)
          output = os.path.join(directory, 'evodag-%s')
          for k, m in enumerate(self.models):
              m.graphviz(output % k, **kwargsf graphviz(self, directory, **kwargs):
          "Directory to store the graphviz models"
          import os
          if not os.path.isdir(directory):
              os.mkdir(directory)
          output = os.path.join(directory, 'evodag-%s')
          for k, m in enumerate(self.models):
              m.graphviz(output % k, **kwargs)
docs: Directory to store the graphviz models