code: def test_trace_metadata_setter_with_existing_values():
      t = Trace(name="test")
      t.metadata = {"k1": "v1"}
      t.metadata = {"k2": "v2"}
      assert t.metadata == {"k1": "v1", "k2": "v2"}
  
imports: import time
  import pytest
  from wandb.sdk.data_types.trace_tree import Span, SpanKind, StatusCode, Trace
label_desc: Use image node_id 24 for calling a global function with example usage: test_trace_metadata_setter_with_existing_values() without return types