def __init__(self, locator=None):
        """
        Initialise an instance, using the specified locator
        to locate distributions.
        """
        self.locator = locator or default_locator
        self.scheme = get_scheme(self.locator.scheme)

        Initialise an instance, using the specified locator
        to locate distributions.
        
product/gradle-plugin/src/main/python/pip/_vendor/distlib/locators.py