code: def save_to_file(self, out_file):
          
          correlation_matrix = self.get_correlation_matrix_from_columns()
          cr_plot.create_correlation_matrix_plot(
              correlation_matrix, self.title, self.headers_to_test)
  
          fig = pyplot.gcf()  # get reference to figure
          fig.set_size_inches(23.4, 23.4)
          pyplot.savefig(out_file, dpi=120)
docs: Saves correlation matrix of selected headers
  
          :param out_file: Output file