code: def test_error_with_prefix_default_category_dict_not_complete(
      dummies_with_unassigned,
  ):
      with pytest.raises(
          ValueError,
          match=(
              r"Length of 'default_category' \(1\) did not match "
              r"the length of the columns being encoded \(2\)"
          ),
      ):
          from_dummies(
              dummies_with_unassigned,
              sep="_",
              default_category={"col1": "x"},
          )
  
imports: import numpy
  import pytest
  from pandas import DataFrame, Series, from_dummies, get_dummies
  import pandas._testing
label_desc: Use image node_id 13 for calling a global function with example usage: test_error_with_prefix_default_category_dict_not_complete(dummies_with_unassigned) without return types