How to use the amuse.community.agama.interface.Agama function in amuse

def test2(self):
        particles=new_plummer_model(10000)
        instance = Agama(type="Multipole", particles=particles)
        result=instance.get_potential_at_point(
            0.|generic_unit_system.length,
            0.|generic_unit_system.length,
            0.|generic_unit_system.length,
            0.|generic_unit_system.length)
        self.assertLess(abs(result/(-16./3/3.1416|
            generic_unit_system.length**2/generic_unit_system.time**2) - 1), 0.04)

        scaleM=1234|units.MSun
        scaleR=5.6 |units.parsec
        converter=nbody_system.nbody_to_si(scaleM,scaleR)
        particles=new_plummer_model(20000, convert_nbody=converter)
        instance = Agama(converter, type="Multipole", particles=particles)
        x=3.|units.parsec
        y=4.|units.parsec
        z=5.|units.parsec

z |generic_unit_system.length)
        self.assertAlmostEqual(result.value_in(
            generic_unit_system.length**2/generic_unit_system.time**2), -M/(r+a), places=14)
        result=instance.get_gravity_at_point(
            0.|generic_unit_system.length,
            x |generic_unit_system.length,
            y |generic_unit_system.length,
            z |generic_unit_system.length)
        self.assertAlmostEqual(result[0].value_in(
            generic_unit_system.length/generic_unit_system.time**2), -M/(r+a)**2 * x/r, places=14)
        self.assertAlmostEqual(result[0],result[2]/3, places=14)

        scaleM=2.345678|units.MSun
        scalea=7.654321|units.parsec
        converter=nbody_system.nbody_to_si(scaleM, scalea)
        instance = Agama(converter, type="Dehnen", mass=M*scaleM, scaleradius=a*scalea)
        result=instance.get_gravity_at_point(
            0.|generic_unit_system.length, x*scalea, y*scalea, z*scalea)
        scale=M/(r+a)**2 *scaleM/scalea**2*constants.G
        self.assertAlmostEqual(result[0], scale * x/r, places=10)
        instance.stop()

def test2(self):
        particles=new_plummer_model(10000)
        instance = Agama(type="Multipole", particles=particles)
        result=instance.get_potential_at_point(
            0.|generic_unit_system.length,
            0.|generic_unit_system.length,
            0.|generic_unit_system.length,
            0.|generic_unit_system.length)
        self.assertLess(abs(result/(-16./3/3.1416|
            generic_unit_system.length**2/generic_unit_system.time**2) - 1), 0.04)

        scaleM=1234|units.MSun
        scaleR=5.6 |units.parsec
        converter=nbody_system.nbody_to_si(scaleM,scaleR)
        particles=new_plummer_model(20000, convert_nbody=converter)
        instance = Agama(converter, type="Multipole", particles=particles)
        x=3.|units.parsec
        y=4.|units.parsec
        z=5.|units.parsec
        r=(x*x+y*y+z*z)**0.5
        result=instance.get_gravity_at_point(0|units.parsec, x, y, z)
        expected=-constants.G*scaleM/(r*r+(3*3.1416/16*scaleR)**2)**1.5*x
        self.assertLess(abs(result[0]/expected-1), 0.03)
        self.assertLess(abs(result[2]/result[0]-z/x), 0.03)
        instance.stop()

def test1(self):
        M=10.
        a=2.
        x=1.
        y=2.
        z=3.
        r=(x*x+y*y+z*z)**0.5
        instance = Agama(type="Dehnen",
            mass=M|generic_unit_system.mass, scaleRadius=a|generic_unit_system.length)
        result=instance.get_potential_at_point(
            0.|generic_unit_system.length,
            x |generic_unit_system.length,
            y |generic_unit_system.length,
            z |generic_unit_system.length)
        self.assertAlmostEqual(result.value_in(
            generic_unit_system.length**2/generic_unit_system.time**2), -M/(r+a), places=14)
        result=instance.get_gravity_at_point(
            0.|generic_unit_system.length,
            x |generic_unit_system.length,
            y |generic_unit_system.length,
            z |generic_unit_system.length)
        self.assertAlmostEqual(result[0].value_in(
            generic_unit_system.length/generic_unit_system.time**2), -M/(r+a)**2 * x/r, places=14)
        self.assertAlmostEqual(result[0],result[2]/3, places=14)

# set up parameters:
    N = 100
    W0 = 3
    Rinit = 50. | units.parsec
    timestep = 0.01 | units.Myr
    Mcluster = 4.e4 | units.MSun
    Rcluster = 0.7 | units.parsec
    converter = nbody_system.nbody_to_si(Mcluster,Rcluster)

    # create a globular cluster model
    particles = new_king_model(N, W0, convert_nbody=converter)
    particles.radius = 0.0| units.parsec
    cluster = Hermite(converter, parameters=[("epsilon_squared", (0.01 | units.parsec)**2)], channel_type='sockets')

    # create the external potential of the Galaxy
    galaxy = Agama(converter, type="Dehnen", gamma=1.8, \
        rscale=1000.| units.parsec, mass=1.6e10 | units.MSun, channel_type='sockets')

    # shift the cluster to an orbit around Galactic center
    acc,_,_ = galaxy.get_gravity_at_point(0|units.kpc, Rinit, 0|units.kpc, 0|units.kpc)
    vcirc = (-acc * Rinit)**0.5
    print("Vcirc=%f km/s" % vcirc.value_in(units.kms))
    particles.x  += Rinit
    particles.vy += vcirc
    cluster.particles.add_particles(particles)

    # set up bridge; cluster is evolved under influence of the galaxy
    sys = bridge(verbose=False)
    sys.add_system(cluster, (galaxy,), False)

    # evolve and make plots
    times = units.Myr([0.,0.2,0.4,0.6,0.8,1.0,1.2,1.4])