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 find_first_remote_branch(remotes: Sequence['Remote'], branch_name: str) -> 'RemoteReference':
    """Find the remote branch matching the name of the given branch or raise InvalidGitRepositoryError"""
    for remote in remotes:
        try:
            return remote.refs[branch_name]
        except IndexError:
            continue
        # END exception handling
    # END for remote
    raise InvalidGitRepositoryError("Didn't find remote branch '%r' in any of the given remotes" % branch_name)