How to use the poetry.packages.Dependency function in poetry

def test_accepts_prerelease():
    dependency = Dependency("A", "^1.0", allows_prereleases=True)
    package = Package("A", "1.4-beta.1")

    assert dependency.accepts(package)

package = repo.package("ipython", "5.7.0")

    assert "ipython" == package.name
    assert "5.7.0" == package.version.text
    assert "*" == package.python_versions

    expected = [
        Dependency("appnope", "*"),
        Dependency("backports.shutil-get-terminal-size", "*"),
        Dependency("colorama", "*"),
        Dependency("decorator", "*"),
        Dependency("pathlib2", "*"),
        Dependency("pexpect", "*"),
        Dependency("pickleshare", "*"),
        Dependency("prompt-toolkit", ">=1.0.4,<2.0.0"),
        Dependency("pygments", "*"),
        Dependency("setuptools", ">=18.5"),
        Dependency("simplegeneric", ">0.8"),
        Dependency("traitlets", ">=4.2"),
        Dependency("win-unicode-console", ">=0.5"),
    ]
    assert expected == package.requires

    assert 'python_version == "2.7"' == str(package.requires[1].marker)
    assert 'sys_platform == "win32" and python_version < "3.6"' == str(
        package.requires[12].marker
    )
    assert 'python_version == "2.7" or python_version == "3.3"' == str(
        package.requires[4].marker
    )
    assert 'sys_platform != "win32"' == str(package.requires[5].marker)

def test_get_package_information_fallback_read_setup():
    repo = MockRepository()

    package = repo.package("jupyter", "1.0.0")

    assert package.name == "jupyter"
    assert package.version.text == "1.0.0"
    assert (
        package.description
        == "Jupyter metapackage. Install all the Jupyter components in one go."
    )

    if PY35:
        assert package.requires == [
            Dependency("notebook", "*"),
            Dependency("qtconsole", "*"),
            Dependency("jupyter-console", "*"),
            Dependency("nbconvert", "*"),
            Dependency("ipykernel", "*"),
            Dependency("ipywidgets", "*"),
        ]

Dependency("constantly", ">=15.1"),
        Dependency("hyperlink", ">=17.1.1"),
        Dependency("incremental", ">=16.10.1"),
        Dependency("PyHamcrest", ">=1.9.0"),
        Dependency("zope.interface", ">=4.4.2"),
    ]

    expected_extras = {
        "all_non_platform": [
            Dependency("appdirs", ">=1.4.0"),
            Dependency("cryptography", ">=1.5"),
            Dependency("h2", ">=3.0,<4.0"),
            Dependency("idna", ">=0.6,!=2.3"),
            Dependency("priority", ">=1.1.0,<2.0"),
            Dependency("pyasn1", "*"),
            Dependency("pyopenssl", ">=16.0.0"),
            Dependency("pyserial", ">=3.0"),
            Dependency("service_identity", "*"),
            Dependency("soappy", "*"),
        ]
    }

    for name, deps in expected_extras.items():
        assert expected_extras[name] == sorted(
            package.extras[name], key=lambda r: r.name
        )

package = repo.package("sqlalchemy", "1.2.12")

    assert package.name == "sqlalchemy"
    assert len(package.requires) == 0

    assert package.extras == {
        "mssql_pymssql": [Dependency("pymssql", "*")],
        "mssql_pyodbc": [Dependency("pyodbc", "*")],
        "mysql": [Dependency("mysqlclient", "*")],
        "oracle": [Dependency("cx_oracle", "*")],
        "postgresql": [Dependency("psycopg2", "*")],
        "postgresql_pg8000": [Dependency("pg8000", "*")],
        "postgresql_psycopg2binary": [Dependency("psycopg2-binary", "*")],
        "postgresql_psycopg2cffi": [Dependency("psycopg2cffi", "*")],
        "pymysql": [Dependency("pymysql", "*")],
    }

def test_fallback_can_read_setup_to_get_dependencies():
    repo = MockRepository(fallback=True)

    package = repo.package("sqlalchemy", "1.2.12")

    assert package.name == "sqlalchemy"
    assert len(package.requires) == 0

    assert package.extras == {
        "mssql_pymssql": [Dependency("pymssql", "*")],
        "mssql_pyodbc": [Dependency("pyodbc", "*")],
        "mysql": [Dependency("mysqlclient", "*")],
        "oracle": [Dependency("cx_oracle", "*")],
        "postgresql": [Dependency("psycopg2", "*")],
        "postgresql_pg8000": [Dependency("pg8000", "*")],
        "postgresql_psycopg2binary": [Dependency("psycopg2-binary", "*")],
        "postgresql_psycopg2cffi": [Dependency("psycopg2cffi", "*")],
        "pymysql": [Dependency("pymysql", "*")],
    }

def test_get_package_information_skips_dependencies_with_invalid_constraints():
    repo = MockRepository()

    package = repo.package("python-language-server", "0.21.2")

    assert package.name == "python-language-server"
    assert package.version.text == "0.21.2"
    assert (
        package.description == "Python Language Server for the Language Server Protocol"
    )

    assert sorted(package.requires, key=lambda r: r.name) == [
        Dependency("configparser", "*"),
        Dependency("future", ">=0.14.0"),
        Dependency("futures", "*"),
        Dependency("jedi", ">=0.12"),
        Dependency("pluggy", "*"),
        Dependency("python-jsonrpc-server", "*"),
    ]

    all_extra = package.extras["all"]

    # rope>-0.10.5 should be discarded
    assert sorted(all_extra, key=lambda r: r.name) == [
        Dependency("autopep8", "*"),
        Dependency("mccabe", "*"),
        Dependency("pycodestyle", "*"),
        Dependency("pydocstyle", ">=2.0.0"),
        Dependency("pyflakes", ">=1.6.0"),
        Dependency("yapf", "*"),
    ]

def test_fallback_can_read_setup_to_get_dependencies():
    repo = MockRepository(fallback=True)

    package = repo.package("sqlalchemy", "1.2.12")

    assert package.name == "sqlalchemy"
    assert len(package.requires) == 0

    assert package.extras == {
        "mssql_pymssql": [Dependency("pymssql", "*")],
        "mssql_pyodbc": [Dependency("pyodbc", "*")],
        "mysql": [Dependency("mysqlclient", "*")],
        "oracle": [Dependency("cx_oracle", "*")],
        "postgresql": [Dependency("psycopg2", "*")],
        "postgresql_pg8000": [Dependency("pg8000", "*")],
        "postgresql_psycopg2binary": [Dependency("psycopg2-binary", "*")],
        "postgresql_psycopg2cffi": [Dependency("psycopg2cffi", "*")],
        "pymysql": [Dependency("pymysql", "*")],
    }

assert "*" == package.python_versions

    expected = [
        Dependency("appnope", "*"),
        Dependency("backports.shutil-get-terminal-size", "*"),
        Dependency("colorama", "*"),
        Dependency("decorator", "*"),
        Dependency("pathlib2", "*"),
        Dependency("pexpect", "*"),
        Dependency("pickleshare", "*"),
        Dependency("prompt-toolkit", ">=1.0.4,<2.0.0"),
        Dependency("pygments", "*"),
        Dependency("setuptools", ">=18.5"),
        Dependency("simplegeneric", ">0.8"),
        Dependency("traitlets", ">=4.2"),
        Dependency("win-unicode-console", ">=0.5"),
    ]
    assert expected == package.requires

    assert 'python_version == "2.7"' == str(package.requires[1].marker)
    assert 'sys_platform == "win32" and python_version < "3.6"' == str(
        package.requires[12].marker
    )
    assert 'python_version == "2.7" or python_version == "3.3"' == str(
        package.requires[4].marker
    )
    assert 'sys_platform != "win32"' == str(package.requires[5].marker)

else:
                package.files = lock_data["metadata"]["files"][info["name"]]

            package.python_versions = info["python-versions"]
            extras = info.get("extras", {})
            if extras:
                for name, deps in extras.items():
                    package.extras[name] = []

                    for dep in deps:
                        m = re.match(r"^(.+?)(?:\s+\((.+)\))?$", dep)
                        dep_name = m.group(1)
                        constraint = m.group(2) or "*"

                        package.extras[name].append(
                            poetry.packages.Dependency(dep_name, constraint)
                        )

            if "marker" in info:
                package.marker = parse_marker(info["marker"])
            else:
                # Compatibility for old locks
                if "requirements" in info:
                    dep = poetry.packages.Dependency("foo", "0.0.0")
                    for name, value in info["requirements"].items():
                        if name == "python":
                            dep.python_versions = value
                        elif name == "platform":
                            dep.platform = value

                    split_dep = dep.to_pep_508(False).split(";")
                    if len(split_dep) > 1: