code: def _filter_by_minimum_term_frequency(self, all_categories, df):
      if (
          self.scatterchartdata.terms_to_include is None
          and self.scatterchartdata.dont_filter is False
      ):
          df = df[
              lambda df: (
                  df[[str(c) + " freq" for c in all_categories]].sum(
                      axis=1
                  )
                  > self.scatterchartdata.minimum_term_frequency
              )
          ]
      return df
  
imports: import logging
  import sys
  import numpy
  import pandas
  from scipy.stats import rankdata
  from scattertext.PValGetter import get_p_vals
  from scattertext.Scalers import percentile_min, percentile_alphabetical
  from scattertext.ScatterChartData import ScatterChartData
  from scattertext.TermDocMatrixFilter import filter_bigrams_by_pmis, filter_out_unigrams_that_only_occur_in_one_bigram
  from scattertext.termscoring import ScaledFScore
  from scattertext.termscoring.RankDifference import RankDifference
  from scattertext.termscoring.CornerScore import CornerScore
label_desc: Use image node_id 20 for calling the ScatterChart obj's underlying member method code with example usage: obj._filter_by_minimum_term_frequency(all_categories, df) and returns: df