code: def test_multiple_named_namespaces_multiple_features_multiple_lines():
      df = pd.DataFrame(
          {
              "y": [1, -1],
              "a": [2, 3],
              "b": ["x1", "x2"],
              "c": [36.4, 47.8],
          }
      )
      ns1 = Namespace(name="FirstNameSpace", features=Feature("a"))
      ns2 = Namespace(
          name="DoubleIt",
          value=2,
          features=[Feature("b"), Feature("c")],
      )
      label = SimpleLabel("y")
      conv = DFtoVW(df=df, label=label, namespaces=[ns1, ns2])
      lines_list = conv.convert_df()
      assert lines_list == [
          "1 |FirstNameSpace a:2 |DoubleIt:2 b=x1 c:36.4",
          "-1 |FirstNameSpace a:3 |DoubleIt:2 b=x2 c:47.8",
      ]
  
imports: import pytest
  import pandas
  from vowpalwabbit.dftovw import ContextualbanditLabel, DFtoVW, Feature, MulticlassLabel, MultiLabel, Namespace, SimpleLabel
label_desc: Use image node_id 14 for calling a global function with example usage: test_multiple_named_namespaces_multiple_features_multiple_lines() without return types