content: import os
  
  # nose2
  os.system(
      "nose2 --with-coverage --coverage pyecharts "
      "--coverage-config .coveragerc -s test"
  )
  
  # pytest
  os.system("pytest -cov-config=.coveragerc --cov=./ test/")
  
  # flake8 for code linting
  os.system("flake8 --exclude=build,example,images --max-line-length=89 --ignore=F401")
  