def load(self, filename, create_if_missing=True):
        filename = Path(filename)
        if not filename.exists() and create_if_missing:
            self.load_pip_requirements()
            with filename.open("w") as f:
                f.write(yaml.dump(self.serialized, default_flow_style=False,
                                  encoding=None))
            self.filename = filename
            return self.save(filename)
        with filename.open() as f:
            for group, requirements in yaml.load(f.read()).items():
                for requirement in requirements:
                    self[group].add(Requirement.coerce(requirement))
        self.filename = filename
def _split_vertical(container):
		r1 = None
		r2 = None
		min_w = int(W_RATIO*container.h)+1
		if container.w < 2*min_w:
			return None
		r1 = Container(container.x,container.y,randint(min_w, container.w-min_w),container.h)
		r2 = Container(container.x+r1.w,container.y,container.w-r1.w,container.h)
		return [r1, r2]