code: def test_optimizer_init():
      optimizer = Optimizer(
          learn_rate=0.123,
          use_averages=False,
          use_radam=True,
          L2=0.1,
          L2_is_weight_decay=False,
      )
      _, gradient = optimizer(
          (0, "x"), numpy.zeros((1, 2)), numpy.zeros(0)
      )
      assert numpy.array_equal(gradient, numpy.zeros(0))
      W = numpy.asarray([1.0, 0.0, 0.0, 1.0], dtype="f").reshape((4,))
      dW = numpy.asarray([[-1.0, 0.0, 0.0, 1.0]], dtype="f").reshape(
          (4,)
      )
      optimizer((0, "x"), W, dW)
      optimizer = Optimizer(learn_rate=0.123, beta1=0.1, beta2=0.1)
      optimizer((1, "x"), W, dW)
  
file_path: thinc/thinc/tests/test_optimizers.py
imports: import numpy
  import pytest
  from thinc.api import Optimizer, registry
label_desc: Use image node_id 9 for calling a global function with example usage: test_optimizer_init() without return types