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 runcmd(cmd, **kw):  # same code as in getlino.py
    """Run the cmd similar as os.system(), but stop when Ctrl-C."""
    # kw.update(stdout=subprocess.PIPE)
    # kw.update(stderr=subprocess.STDOUT)
    kw.update(shell=True)
    kw.update(universal_newlines=True)
    kw.update(check=True)
    # subprocess.check_output(cmd, **kw)
    subprocess.run(cmd, **kw)
    # os.system(cmd)