How to use the pybuilder.core.Dependency function in pybuilder

def test_dependency_should_be_lesser_than_other_when_name_is_lesser(self):
        dependency = Dependency("foo")
        other_dependency = Dependency("foa")
        self.assertTrue(dependency > other_dependency)

def test_should_install_dependency_with_version(self, exec_command, get_package_version, constraint_file):
        dependency = Dependency("spam", "0.1.2")

        install_dependency(self.logger, self.project, dependency)

        exec_command(
            PIP_EXEC_STANZA + ["install", 'spam>=0.1.2'], ANY, env=ANY, shell=False)

def test_should_install_dependency_insecurely_when_property_is_set(self, exec_command,
                                                                       get_package_version,
                                                                       constraint_file):
        dependency = Dependency("spam")
        self.project.set_property("install_dependencies_insecure_installation", ["spam"])

        install_dependency(self.logger, self.project, dependency)

        exec_command(
            PIP_EXEC_STANZA + ["install", "--allow-unverified", "spam", "--allow-external", "spam", 'spam'],
            ANY, env=ANY, shell=False)

def test_dependency_should_not_be_equal_to_other_when_names_differ(self):
        dependency = Dependency("foo")
        other_dependency = Dependency("foa")
        self.assertFalse(dependency == other_dependency)

def setUp(self):
        self.logger = Mock(Logger)
        self.dependencies_to_install_with_pip = [Dependency('test'), Dependency('pip')]
        self.dependencies_to_install_without_pip = [Dependency('test'), Dependency('test2')]
        from pybuilder import pip_common, pip_utils
        self.pip_common_object = pip_common.Version("1.2.3")
        self.pip_utils_method = pip_utils.pip_install

def test_dependency_should_be_unequal_to_other_when_names_differ(self):
        dependency = Dependency("foo")
        other_dependency = Dependency("foa")
        self.assertTrue(dependency != other_dependency)

def test_requirements_file_should_not_be_equal_to_dependency(self):
        dependency = Dependency("foo")
        requirements = RequirementsFile("requirements.txt")

        self.assertFalse(dependency == requirements)

def test_dependency_should_be_lesser_than_other_when_name_is_lesser(self):
        dependency = Dependency("foo")
        other_dependency = Dependency("foa")
        self.assertTrue(dependency > other_dependency)

def test_requirements_should_always_be_greater_than_dependencies(self):
        dependency = Dependency("foo")
        requirements = RequirementsFile("requirements.txt")

        self.assertTrue(requirements > dependency)

def as_pip_install_target(mixed):
    arguments = []
    targets = as_list(mixed)

    for target in targets:
        if isinstance(target, RequirementsFile):
            arguments.extend(("-r", target.name))
        elif isinstance(target, Dependency):
            if target.url:
                arguments.append(target.url)
            else:
                arguments.append("{0}{1}".format(target.name, build_dependency_version_string(target)))
        else:
            arguments.append(str(target))

    return arguments