Fix test case

[gogasca]

Run pip install pytest
Collecting pytest
  Downloading https://files.pythonhosted.org/packages/19/cf/711f1d887cb92c5155c9a1eb338f1b5d2411b50e4492a3b20e4a188a22b2/pytest-5.3.2-py3-none-any.whl (234kB)
Collecting attrs>=17.4.0
  Downloading https://files.pythonhosted.org/packages/a2/db/4313ab3be961f7a763066401fb77f7748373b6094076ae2bda2806988af6/attrs-19.3.0-py2.py3-none-any.whl
Requirement already satisfied: packaging in /opt/hostedtoolcache/Python/3.6.9/x64/lib/python3.6/site-packages (from pytest) (16.8)
Collecting wcwidth
  Downloading https://files.pythonhosted.org/packages/7e/9f/526a6947247599b084ee5232e4f9190a38f398d7300d866af3ab571a5bfe/wcwidth-0.1.7-py2.py3-none-any.whl
Requirement already satisfied: importlib-metadata>=0.12; python_version < "3.8" in /opt/hostedtoolcache/Python/3.6.9/x64/lib/python3.6/site-packages (from pytest) (1.3.0)
Requirement already satisfied: more-itertools>=4.0.0 in /opt/hostedtoolcache/Python/3.6.9/x64/lib/python3.6/site-packages (from pytest) (8.0.2)
Collecting pluggy<1.0,>=0.12
  Downloading https://files.pythonhosted.org/packages/a0/28/85c7aa31b80d150b772fbe4a229487bc6644da9ccb7e427dd8cc60cb8a62/pluggy-0.13.1-py2.py3-none-any.whl
Collecting py>=1.5.0
  Downloading https://files.pythonhosted.org/packages/76/bc/394ad449851729244a97857ee14d7cba61ddb268dce3db538ba2f2ba1f0f/py-1.8.0-py2.py3-none-any.whl (83kB)