How to use the iotedgedev.envvars.EnvVars function in iotedgedev

def test_container_registry_server_key_missing_sys_exit():
    output = Output()
    envvars = EnvVars(output)
    with pytest.raises(ValueError):
        envvars.get_envvar("CONTAINER_REGISTRY_SERVER_UNITTEST", required=True)

def test_unique_container_registry_username_tokens():
    unique = set()
    length_container_registry_username = len('container_registry_username')
    is_unique = True
    output = Output()
    envvars = EnvVars(output)
    envvars.load()
    for key in os.environ:
        key = key.lower()
        if key.startswith('container_registry_username'):
            token = key[length_container_registry_username:]
            if token not in unique:
                unique.add(token)
            else:
                is_unique = False
    assert is_unique

def test_in_command_list_empty_2():
    output = Output()
    envvars = EnvVars(output)
    assert not envvars.in_command_list("solution new test_solution", ["init", "e2e", "", "new", "simulator stop"])

def test_default_container_registry_password_value_exists_or_returns_empty_string():
    output = Output()
    envvars = EnvVars(output)
    password = envvars.get_envvar("CONTAINER_REGISTRY_PASSWORD")
    assert password is not None

def test_default_container_registry_server_value_exists():
    output = Output()
    envvars = EnvVars(output)
    server = envvars.get_envvar("CONTAINER_REGISTRY_SERVER")
    assert server is not None

def test_additional_container_registry_map_has_val(setup_test_env):
    output = Output()
    envvars = EnvVars(output)
    envvars.load()
    assert len(envvars.CONTAINER_REGISTRY_MAP) == 2
    assert 'UNITTEST' in envvars.CONTAINER_REGISTRY_MAP.keys()
    assert envvars.CONTAINER_REGISTRY_MAP['UNITTEST'].server == 'unittest.azurecr.io'
    assert envvars.CONTAINER_REGISTRY_MAP['UNITTEST'].username == 'username'
    assert envvars.CONTAINER_REGISTRY_MAP['UNITTEST'].password == 'password'

def test_is_terse_command_empty():
    output = Output()
    envvars = EnvVars(output)
    assert envvars.is_terse_command("")

def test_unique_container_registry_password_tokens():
    unique = set()
    length_container_registry_password = len('container_registry_password')
    is_unique = True
    output = Output()
    envvars = EnvVars(output)
    envvars.load()
    for key in os.environ:
        key = key.lower()
        if key.startswith('container_registry_password'):
            token = key[length_container_registry_password:]
            if token not in unique:
                unique.add(token)
            else:
                is_unique = False
    assert is_unique

import pytest
import shutil
import time

from iotedgedev.compat import PY35
from iotedgedev.envvars import EnvVars
from iotedgedev.output import Output

from .utility import get_docker_os_type
from .utility import get_platform_type
from .utility import runner_invoke

pytestmark = pytest.mark.e2e

output = Output()
envvars = EnvVars(output)

env_file_name = envvars.get_dotenv_file()
env_file_path = envvars.get_dotenv_path(env_file_name)

root_dir = os.getcwd()
tests_dir = os.path.join(root_dir, 'tests')

test_solution = 'test_solution'
test_solution_dir = os.path.join(tests_dir, test_solution)


@pytest.fixture(scope="module", autouse=True)
def create_solution(request):
    os.chdir(tests_dir)
    result = runner_invoke(['solution', 'new', test_solution])

def deployment_manifest():
    output = Output()
    envvars = EnvVars(output)
    envvars.load()
    utility = Utility(envvars, output)

    def _deployment_manifest(path):
        return DeploymentManifest(envvars, output, utility, path, True)

    return _deployment_manifest