docstr: Gets the name of the label column.
docstr_tok: ["Gets","the","name","of","the","label","column","."]
code: def getLabelColumn(self):
      """Gets the name of the label column."""
      return self.getOrDefault(self.labelColumn)
  
imports: from pyspark.ml import Model, Estimator
  from pyspark.ml.util import DefaultParamsWritable, DefaultParamsReadable
  from sparknlp.common import *
label_desc: Use image node_id 4 for calling the TFNerDLGraphBuilder obj's underlying member method code with example usage: obj.getLabelColumn() and returns: self