How to use the moderngl.next function in moderngl

self.prog['scale'] = (height / width * 0.75, 0.75)

        vertices = np.array([
            1.0, 0.0,
            1.0, 0.0, 0.0, 0.5,

            -0.5, 0.86,
            0.0, 1.0, 0.0, 0.5,

            -0.5, -0.86,
            0.0, 0.0, 1.0, 0.5,
        ])

        self.vbo = self.ctx.buffer(vertices.astype('f4').tobytes())
        self.vao = self.ctx.simple_vertex_array(self.prog, self.vbo, 'vert', 'vert_color')
        self.blend = self.ctx.scope(enable_only=mgl.BLEND)

def __init__(self):
        self.ctx = mgl.create_context()

        self.prog = self.ctx.program(
            vertex_shader='''
                #version 330

                in vec3 vert;

                uniform float z_near;
                uniform float z_far;
                uniform float fovy;
                uniform float ratio;

                uniform vec3 center;
                uniform vec3 eye;
                uniform vec3 up;

def __init__(self, **kwargs):
        super().__init__(**kwargs)

        # self.sampler.filter = (mgl.LINEAR, mgl.LINEAR)
        self.sampler.filter = mgl.LINEAR

        self.sampler.wrap = mgl.REPEAT_X | mgl.REPEAT_Y

img5 = Image.new('RGB', (200, 200), '#fef')
        img6 = Image.new('RGB', (200, 200), '#eff')

        ImageDraw.ImageDraw(img1).text((50, 30), 'i1', '#000', ImageFont.truetype('arial', 128))
        ImageDraw.ImageDraw(img2).text((50, 30), 'i2', '#000', ImageFont.truetype('arial', 128))
        ImageDraw.ImageDraw(img3).text((50, 30), 'i3', '#000', ImageFont.truetype('arial', 128))
        ImageDraw.ImageDraw(img4).text((50, 30), 'i4', '#000', ImageFont.truetype('arial', 128))
        ImageDraw.ImageDraw(img5).text((50, 30), 'i5', '#000', ImageFont.truetype('arial', 128))
        ImageDraw.ImageDraw(img6).text((50, 30), 'i6', '#000', ImageFont.truetype('arial', 128))

        def join(*images):
            return b''.join(img.tobytes('raw', 'RGB', 0, -1) for img in images)

        self.texture = self.ctx.texture_cube((200, 200), 3, join(img1, img2, img3, img4, img5, img6))
        self.sampler = self.ctx.sampler(self.texture)
        self.sampler.filter = mgl.LINEAR
        self.sampler.use()

        obj = Obj.open(data.find('sitting_dummy.obj'))
        self.vbo = self.ctx.buffer(obj.pack('vx vy vz nx ny nz'))
        self.vao = self.ctx.simple_vertex_array(self.prog, self.vbo, 'in_vert', 'in_norm')
        self.scope = self.ctx.scope(mgl.DEPTH_TEST)

def __init__(self, **kwargs):
        super().__init__(**kwargs)

        self.sampler.wrap = mgl.REPEAT_X | mgl.MIRROR_CLAMP_TO_EDGE_Y

def __init__(self):
        self.ctx = mgl.create_context()

        self.prog = self.ctx.program(
            vertex_shader='''
                #version 330

                uniform mat4 Mvp;

                in vec3 in_vert;
                in vec3 in_norm;
                in vec2 in_text;

                out vec3 v_vert;
                out vec3 v_norm;
                out vec2 v_text;

                void main() {

def __init__(self, **kwargs):
        super().__init__(**kwargs)
        self.ctx = mgl.create_context()

        self.prog = self.ctx.program(
            vertex_shader='''
                #version 330

                uniform mat4 Mvp;

                in vec3 in_vert;
                in vec3 in_norm;
                in vec2 in_text;

                out vec3 v_vert;
                out vec3 v_norm;
                out vec2 v_text;

                void main() {