def add(self, elem, replace=False):
        """Add a requirement.

        :param elem: a string or :class:`Requirement` instance.
        :param replace: if `True`, packages in the set with the same name will
            be removed first.
        """
        if isinstance(elem, text_type):
            elem = Requirement.coerce(elem)
        if replace and elem in self:
            self.remove(elem)
        super(Requirements, self).add(elem)
def __init__(self, resolver, proxy_type, key):
        if proxy_type == "file":
            self._method = resolver.get_file_content
        elif proxy_type == "param":
            self._method = resolver.get_parameter_value
        elif proxy_type == "secret":
            self._method = resolver.get_secret_value
        elif proxy_type == "bucket_file":
            self._method = resolver.get_bucket_file
        else:
            raise ValueError("Unknown proxy type %s", proxy_type)
        self._key = key