code: def test_is_float_float64(self):
      self.assertTrue(dtype_utils.is_float("float64"))
  
imports: from keras.backend.common.keras_tensor import KerasTensor
  from keras.testing import test_case
  from keras.utils import dtype_utils
label_desc: Use image node_id 3 for calling the IsFloatTests obj's underlying member method code with example usage: obj.test_is_float_float64() without return types