code: def test_nnEstimator_fit_with_non_default_featureCol(self):
      model = Sequential().add(Linear(2, 2))
      criterion = MSECriterion()
      estimator = (
          NNEstimator(
              model, criterion, SeqToTensor([2]), SeqToTensor([2])
          )
          .setBatchSize(4)
          .setLearningRate(0.01)
          .setMaxEpoch(1)
          .setFeaturesCol("abcd")
          .setLabelCol("xyz")
          .setPredictionCol("tt")
      )
  
      data = self.sc.parallelize(
          [
              ((2.0, 1.0), (1.0, 2.0)),
              ((1.0, 2.0), (2.0, 1.0)),
              ((2.0, 1.0), (1.0, 2.0)),
              ((1.0, 2.0), (2.0, 1.0)),
          ]
      )
  
      schema = StructType(
          [
              StructField(
                  "abcd", ArrayType(DoubleType(), False), False
              ),
              StructField("xyz", ArrayType(DoubleType(), False), False),
          ]
      )
      df = self.sqlContext.createDataFrame(data, schema)
      nnModel = estimator.fit(df)
  
      res = nnModel.transform(df)
      assert type(res).__name__ == "DataFrame"
      assert res.select("abcd", "xyz", "tt").count() == 4
  
imports: import errno
  import shutil
  import pytest
  from bigdl.nn.criterion import *
  from bigdl.nn.layer import *
  from bigdl.optim.optimizer import *
  from numpy.testing import assert_allclose
  from pyspark.ml import Pipeline, PipelineModel
  from pyspark.ml.feature import MinMaxScaler
  from pyspark.ml.tuning import ParamGridBuilder
  from pyspark.sql.types import *
  from zoo.common.nncontext import *
  from zoo.feature.common import *
  from zoo.feature.image import *
  from zoo.pipeline.api.keras import layers
  from zoo.pipeline.api.keras.models import Model
  from zoo.pipeline.api.keras.optimizers import Adam
  from zoo.pipeline.nnframes import *
  from zoo.util.tf import *
label_desc: Use image node_id 14 for calling the TestNNClassifer obj's underlying member method code with example usage: obj.test_nnEstimator_fit_with_non_default_featureCol() without return types