How to use the briefcase.integrations.xcode.ensure_xcode_is_installed function in briefcase

def test_installed_with_minimum_version_success(min_version, version, capsys):
    "Check XCode can meet a minimum version requirement."
    sub = mock.MagicMock()
    sub.check_output.return_value = "Xcode {version}\nBuild version 11B500\n".format(
        version=version
    )

    # Check passes without an error.
    ensure_xcode_is_installed(min_version=min_version, sub=sub)

    # Make sure the warning wasn't displayed.
    out = capsys.readouterr().out
    assert "WARNING" not in out

def test_installed_no_minimum_version():
    "If Xcode is installed, but there's no minimum version, check is satisfied."
    sub = mock.MagicMock()
    sub.check_output.return_value = "Xcode 11.2.1\nBuild version 11B500\n"

    # Check passes without an error.
    ensure_xcode_is_installed(sub=sub)

def test_installed_with_minimum_version_failure(min_version, version):
    "Check XCode fail to meet a minimum version requirement."
    sub = mock.MagicMock()
    sub.check_output.return_value = "Xcode {version}\nBuild version 11B500\n".format(
        version=version
    )

    # Check raises an error.
    with pytest.raises(BriefcaseCommandError):
        ensure_xcode_is_installed(min_version=min_version, sub=sub)

def test_not_installed():
    "If Xcode is not installed, raise an error."
    sub = mock.MagicMock()
    sub.check_output.side_effect = subprocess.CalledProcessError(
        cmd=['xcodebuild', '-version'],
        returncode=1
    )

    with pytest.raises(BriefcaseCommandError):
        ensure_xcode_is_installed(sub=sub)

def test_unexpected_version_output(capsys):
    "If xcodebuild returns unexpected output, assume it's ok..."
    sub = mock.MagicMock()
    sub.check_output.return_value = "Wibble Wibble Wibble\n"

    # Check passes without an error...
    ensure_xcode_is_installed(min_version=(11, 2, 1), sub=sub)

    # ...but stdout contains a warning
    out = capsys.readouterr().out
    assert '************' in out

def verify_tools(self):
        if self.host_os != 'Darwin':
            raise BriefcaseCommandError("""
iOS applications require Xcode, which is only available on macOS.
""")

        # Require XCode 10.0.0. There's no particular reason for this
        # specific version, other than it's a nice round number that's
        # not *that* old at time of writing.
        ensure_xcode_is_installed(min_version=(10, 0, 0))