class_docstr: Tests for the `RegistryMapping` class. The RegistryMapping should act as a
  Mapping[Trial, list[Trial]].
class_docstr_tok: ["Tests","for","the","`","RegistryMapping","`","class",".","The","RegistryMapping","should","act","as","a","Mapping","[","Trial",",","list","[","Trial","]","]","."]
docstr: Tests that a new RegistryMapping acts as an empty dict.
docstr_tok: ["Tests","that","a","new","RegistryMapping","acts","as","an","empty","dict","."]
code: def test_init(self):
      """Tests that a new RegistryMapping acts as an empty dict."""
      original = Registry()
      transformed = Registry()
      mapping = RegistryMapping(
          original_registry=original, transformed_registry=transformed
      )
      assert not mapping
      assert len(mapping) == 0
      assert not mapping.keys()
      assert not mapping.values()
      assert not mapping.items()
  
imports: import copy
  import pytest
  from orion.algo.base.registry import Registry, RegistryMapping
  from orion.algo.space import Space
  from orion.core.io.space_builder import SpaceBuilder
  from orion.core.worker.transformer import TransformedSpace, build_required_space
  from orion.core.worker.trial import Trial
label_desc: Use image node_id 1 for calling the TestRegistryMapping obj's underlying member method code with example usage: obj.test_init() without return types