code: def plot(self, x, y, **kwargs):
      self.x = x
      self.y = y
  
file_path: pmdarima/pmdarima/arima/tests/test_arima_diagnostics.py
imports: from pmdarima.datasets import load_lynx
  from pmdarima.arima import ARIMA
  from unittest.mock import patch
  import pytest
label_desc: Use image node_id 5 for calling the MockMPLAxis obj's underlying member method code with example usage: obj.plot(x, y) without return types