code: def add_new_numerical_cols(self, new_feature_names):
      # add to our vocabulary
      for feature_name in new_feature_names:
          if feature_name not in self.vocabulary_:
              self.feature_names_.append(feature_name)
              self.vocabulary_[feature_name] = len(self.vocabulary_)
              self.additional_numerical_cols.append(feature_name)
  
      return self
  
imports: from array import array
  import numbers
  from operator import itemgetter
  import numpy
  import pandas
  import scipy.sparse
  from sklearn.base import BaseEstimator, TransformerMixin
  from sklearn.externals import six
  from auto_ml.utils import CustomLabelEncoder
label_desc: Use image node_id 8 for calling the DataFrameVectorizer obj's underlying member method code with example usage: obj.add_new_numerical_cols(new_feature_names) and returns: self