code: def abstract_integrator(
      position: np.ndarray,
      momentum: np.ndarray,
      time_step: float,
      state_derivatives_fn: StateDerivativesFnType,
  ) -> Tuple[np.ndarray, np.ndarray]:
      """Signature of an abstract integrator.
  
      An integrator is a function, that given the the current state, a time step,
      and a `state_derivatives_fn` returns the next state.
  
      Args:
          position: array with the position at time t.
          momentum: array with the momentum at time t.
          time_step: integration step size.
          state_derivatives_fn: a function fn, that returns time derivatives of a
              state such fn(position, momentum) -> (dposition_dt, dmomentum_dt)
              where dposition_dt, dmomentum_dt, have the same shapes as
              position, momentum.
  
      Returns:
          Tuple with position and momentum at time `t + time_step`.
  
      """
      raise NotImplementedError("Abstract integrator")
  
imports: import functools
  from typing import Tuple, Callable
  from absl import app
  from frozendict import frozendict
  import jax
  import jax.numpy
  import jraph
  import matplotlib.pyplot
  import numpy
label_desc: Use image node_id 10 for calling a global function with example usage: abstract_integrator(position, momentum, time_step, state_derivatives_fn) without return types