def remove(self, elem):
        """Remove a requirement.

        :param elem: a string or :class:`Requirement` instance.
        """
        if isinstance(elem, text_type):
            for requirement in self:
                if requirement.package == elem:
                    return super(Requirements, self).remove(requirement)
        return super(Requirements, self).remove(elem)
def __init__(
        self,
        new_item_default_value,
        min_size=0,
        max_size=None,
        item_spacing=ItemBox.ITEM_SPACING,
        max_width=None,
        max_height=None,
        *args,
        **kwargs):
    """
    Parameters: